We do not know when human societies first felt the need to communicate with each other, but it is safe to assume that they did so from the very earliest times. We know that diplomatic status existed very early and it is both evident and instructive why it should have been so. If it has been decided that it may be better to hear the message than to eat the messenger, then there have to be rules about who a legitimate messenger is, and there have to be sanctions which will ensure his uneatability. The earliest diplomats were a response to a felt need for a mechanism to convey messages between societies safely and reliably. It is instructive to note that right from the beginning, diplomacy, even in its crudest forms, evolved in response to political needs reciprocally felt. It has continued and is continuing thus until today and we shall shortly look at some outstanding and complex examples of the process in action. Once diplomacy actually existed and was conceded to be irreplaceably useful, a reverse factor also became possible. The nature and functioning of the diplomatic machine at any particular historical moment could of itself shape the way in which principals - whoever they might be - conducted their exchanges. Thus it has occasionally occurred that functions which had developed within diplomacy came to create a particular international activity simply because they existed. We will, therefore, look at an example of that process as well.

Of course, sometimes what the machine could not do, or could not be seen to be doing without damaging its basic function, could be done by other means - by Secret Services, for example, or by hired assassins. But sometimes it just meant that what could not be done was not done and opportunities were lost. For this purpose, perhaps one example will suffice. In the period just before 1914, when most foreign services were not equipped to handle commercial matters, the British Board of Trade - the then Ministry of Commerce - asked the Foreign Office to provide information about arms manufacture in Imperial Russia. The Ambassador, Sir George Buchanan, replied to this enquiry that he had not been sent as His Majesty’s Ambassador to the Russian Court to do arithmetical computations for the Board of Trade.

Let us begin by giving some outstanding examples of the process where an unfolding international and diplomatic need evoked a corresponding addition or development in the machinery of diplomacy. This has certainly been the more usual process of modification. The growth of very complete - perhaps too complete - systems for the giving and checking of full powers was a reflection of the increasing significance of diplomatic activity and the greater risk of serious harm flowing from embassies being disavowed. The habit of issuing minute instructions, and the consequential almost hysterical desire on the part of others to know what they contained in advance of negotiations, was evoked both by the emergence of greater central control of diplomatic activity and by the greater potential damage a careless or over confident ambassador could cause(2) . And both of these again reflected a rising level of diplomatic traffic. The evolution of foreign ministries followed from the desire of rulers and their ministers to maintain a continuous flow of diplomatic business in which cross relationships between diplomatic partners, between internal sources of political influence and between differing issues could be carefully followed and controlled. To do this successfully, and to have instantly available knowledge of current obligations and commitments required an institutional memory obtainable only through a properly managed single foreign ministry archive(3) .

These kinds of development occasionally engendered reluctance from contemporary traditionalists. None, however, encountered the fierce opposition and disapproval from the principals themselves that accompanied the emergence of the resident ambassador. There could be no doubt that this was an inescapable response to particular circumstances otherwise it could not have triumphed over the objections of the proprietors of the system itself. The origin of the problem lay in a change of emphasis in the purpose of diplomacy. Internal circumstances in northern Italy in the renaissance period had produced a highly competitive group of small city states, each directly bordering others, none able to triumph over the others either directly or in alliance groups. The most significant - Venice - was not concerned with territorial power so much as trading expansion. External circumstances for the time being provided no threat of intervention. The Byzantine Empire was in its final decline, the Muslim advance had stopped short in the eastern Mediterranean and the development of centres of political power in northern Europe was still in gestation. The result locally was a stalemate: war, apart from being an inconvenient way of extruding power for very small entities - mercenaries notwithstanding, had proved to be incapable of giving victory to any state or group of states. The attempt to gain a sudden and final advantage by means of a great diplomatic coup became an obsessive preoccupation. It might be achieved by constructing the so far elusive winning combination of states; but it might also be achieved by altering the balance of power by subverting the regimes of neighbouring states. Neither Popes nor secular rulers would necessarily refuse to stoop even to poison in this regard, but more usually sought to operate by creating or supporting opposition groups in the hope of due reward when they had clawed their way to power. It was not a pretty picture nor did its apologists suggest otherwise(4) .

Ugly or merely pragmatic, the international situation had produced a new diplomatic need. Whereas, with the exception of the Byzantine Empire, the main thrust of previous diplomatic activity had been to convey messages and the answers to messages from one principal to another, often spun out over long periods of time, the priority had now become the acquisition of knowledge about the political and military situation of others, the information to be reported with maximum speed and secrecy. Domestic security and external advantage both demanded it. The functioning of the system, however, only reflected the previous need. Embassies occurred ad hoc induced either by a particular issue about which information needed to be exchanged or by a ceremonial occasion - e.g. a funeral or an accession or a wedding. The stay with the host was likely to be relatively short, if luxurious, and the opportunities for spying or interference were naturally very restricted. The only practical answer was to keep a representative on the spot and have him report by courier - so secretly that a whole new range of possible ways of concealing documents came into vogue which make swallowing contraceptives full of drugs seem crude by comparison.

The resident ambassador thus appeared. Martin Wight said that he represented the "master-institution’’ of western diplomatic development(5) . The rulers of the period, however, objected to his existence in the strongest terms and from time to time cleared them all out. But as much as they did not want them to report on their domestic situations or indeed to intervene in them, they wanted just as much to receive such information and have such opportunities in respect of others; and the stresses of the contemporary international environment enforced a reciprocal if unwilling tolerance of the existence of permanent representatives(6) . Their usefulness entrenched them, although they did not immediately supplant the older temporary missions, which simply carried on, gradually losing business to the residents and becoming finally purely ceremonial.

It was to take over a hundred years before this development was complete and the slow pace was partly due to the patchy emergence of the fully sovereign and secularized state across the rest of Europe. It was this evolution which led to the gradual restriction of diplomatic representation to states and thus to the office of ambassador achieving greater prominence as the sole international extrusion of his ruler’s power and policy. The conjunction of these two factors contributed to the increasing acceptance of the significant role of the permanent resident embassy. The other delaying factor arose from the intense diplomatic complications caused by the corrosive ideological split brought about by the Reformation. This produced sharply fought wars both general and civil and led to a kind of diplomatic "cold war", where embassies of Protestant rulers at Roman Catholic courts and vice versa became the focal point for dissident groups within the host state, possibly sanctuaries for them, where they could attend religious services otherwise banned and develop plots for the future, perhaps to be aided and abetted by the forces of the resident’s principal. Not surprisingly, it was only when the full force of this struggle blew itself out after 1648 that the position of the resident ambassador became generally recognized de jure as well as de facto, as it had been in Italy a hundred years or more earlier.

Later periods produce further examples. Adjustment to the communications revolution of the 19th century and the creation of international organizations first in response to practical requirements and later answering to an overwhelming moral need to sustain peace when the contemporary conduct of war had produced unacceptable casualties. More recently, the diplomatic machine has needed to integrate the need for representation by a rising number of private international organisations concerned with humanitarian and environmental matters with the existing structure of states. In this case, the process is very difficult since the practical point of entry has been on the very edges of the machinery of diplomacy gained through a particular arm of the United Nations system. In this there is more than a resonance of the other form of diplomatic development which was mentioned at the outset: development characterised by shaping a response to a new need by reference to a pre-existing element in the machine(7) . One of the most interesting examples of this second process occurred at the end of the Napoleonic Wars and it repays examination.

The Congress of Vienna was an historically peculiar event in many ways, not least that it was technically at least, an illegitimate meeting, as Metternich typically grasped(8) . The basic assumptions upon which it proceeded were, however, far more significantly odd. Unlike the practice at previous peacemakings, the makers of the Vienna settlement were less concerned about punishing and disabling the vanquished - though quite clear about removing Napoleon himself from further active participation in international politics - than they were about protecting the world from the ravages of an ideology. The extraordinary trajectory of the Napoleonic imperium had left behind a strong sense that what had fuelled its course was not so much the intrinsic power of France, which was correctly sensed never to have been greater than that of the other great powers, but the positive effects of the ideology of the revolution on those who espoused it and the negative effects on the power and security of those who did not(9) . The consequences of concluding that the long and - by contemporary standards - destructive war had in effect been caused by an ideology, rather than a state or a ruler, profoundly affected what the Congress tried to do. It meant that the usual behaviour of states was changed and that jockeying for relative power via shifting alliances was in effect suspended. Indeed, a deliberate effort was made to maintain the wartime coalition, implicitly - explicitly after 1818 - including France, who signed the settlement, for the stated reason of defending the system against any resumption of revolution.

The consequence of this sea change for diplomacy was, to begin with at least, that there appeared to be no means for giving effect to the obvious wish of the powers to institute a kind of cooperative management of the international system. Diplomacy had steadily developed as the means by which sovereign rulers communicated with other sovereign rulers. It was the great assertion of sovereign individuality, functioning in a sometimes avowedly - or sometimes simply politely - adversarial mode, depending on circumstances. If it was asked to give expression to the wish that rulers cooperate on what was intended to be a permanent basis, it was not easy to see how that could be done. Two ideas were tried out, one very traditional, the other uniquely naive. The first was that an extra treaty should be signed in order to give a special force and legitimacy to the settlement as agreed. It was to have been called a Treaty of General Guarantee. For various reasons, though drafted and revised, it was never signed. The second was the Tsar of Russia’s notion that a highly simplified version of the tenets of Christianity - modern terminology would suggest "born again" as the most accurate description - would serve as the basis for a new kind of international security. This was called the "Holy" alliance, and amidst a good deal of covert giggling it was signed in 1815. The other parties did not believe in its likely efficacy, and felt right up to the end of the negotiations, resumed post-Waterloo, that something else was required. More or less in despair, the British delegate, Robert Stewart, Lord Castlereagh, drafted a clause which turned a piece of recently evolved diplomatic practice into the cornerstone of the international system, which, mutatis mutandis, it has remained.

This clause established the peacetime conference as the mechanism by which governments would give expression to their wish for permanent cooperation in the face of a revolutionary threat, or, as later became the case, against any threat of disruption. The idea that the most effective response to a crisis was to call a meeting in peacetime to discuss it before it got out of hand was new. Conferences or congresses had of course been well known devices, but always in the context of bringing an existing war to an end. Such a thicket of protocol had come to surround them, that by the mid-eighteenth century, powers were beginning to try to avoid formal meetings and resorting to informal ones, without traditional rules.(10)  But the main purpose was still the same. Towards the end of the war, there was a final example of this kind of meeting in its traditional form. Late in 1813, Napoleon had allowed his minister Coulaincourt to hint at a possible peace negotiation and the abortive Congress of Prague was the result. To achieve the abortion, the French side resorted to wonderfully old fashioned mechanisms, demanding formal proposals submitted through a mediator and denying the legitimacy of viva voce discussion. The allies drew the correct conclusion that the negotiations were not serious and withdrew(11) .

The failure of the Congress of Prague was almost simultaneous with the events that were to provide the basis upon which the modern peacetime conference was later introduced. After the battle of Leipzig in 1813, which to most observers signaled the coming end of the Napoleonic imperium, there was a general belief that the Emperor must soon sue for peace in order to obtain the best possible terms, and that the sooner he initiated the process, the more of his Empire he would save. The likelihood that negotiations would soon start made it important that an allied response should be more or less immediately available, and for the British who were the most geographically remote of the partners, there was an obvious risk that the first stages of a peace negotiation might take place without their participation. To fend off that possibility, the British Cabinet took the hitherto unheard of step of sending the Foreign Secretary on a personal mission to the continent which began at the very beginning of 1814. From mid-January, Castlereagh joined up with Metternich, the Prussian, Hardenberg, and Czar Alexander I of Russia in Switzerland and the group remained together until the war ended and beyond(12) . The ever extending length of the mission was caused by the refusal of Napoleon to see the apparent logic of his position. To him, anything other than victory in war was synonymous with losing his throne, for he understood that his domestic power was dependent on foreign domination. He thus fought on through appallingly wintry conditions and survived by some of the most remarkable generalship of his career, until the end came in May with the retreat to Paris and his abdication. The continuation of the coalition thus became a more significant objective and achievement than preparing for peace, and it is clear from the course of events that the political direction which was provided by the foreign ministers and rulers was essential in protecting the coalition from breaking up, as all previous ones had done. What in effect had happened was that a de facto rolling conference of the allied powers was established, ready to deal on a daily basis with the thrills and spills of a major alliance at war à l’outrance.

The success of this operation caused its members to proceed in the same way with the making of the Treaty of Paris of May, 1814 and the preparations for the Congress of Vienna, originally scheduled to meet in August of 1814 but persistently postponed until November(13) . The difficulties inherent in creating a major resettlement of Europe were in themselves immense, and the determination of the representatives of the Great Powers to do the job without the participation of others produced major tensions with smaller powers, notably the King of Sweden. But despite the great crisis of December/January over the future of Poland, the core group succeeded in constructing a new European order and did so by including France among the negotiating parties, thus completing the process by which affairs were being conducted essentially by a directorate of all five of the Great Powers.

Initially nobody noticed that what had occurred constituted major revision of the machinery of diplomacy, except in so far as they objected to it as a new and excluding phenomenon. As the settlement proceeded, and particularly after the episode leading to the battle of Waterloo, the notion first adumbrated by Pitt the Younger in 1805 that the final agreement needed some exceptionally definitive and permanent expression grew in strength. As was noted earlier, two possible routes were discussed: the first was the drafting of a special Treaty of General Guarantee. This was redrafted several times, but it fell by the wayside and was never signed. As time passed, the Czar of Russia came to prefer the idea of encapsulating new rules for the international community in a specifically Christian - and, indeed, wholly naive - form; and successfully insisted on the institution of the Holy Alliance in September 1815(14) . From a different point of view, Lord Castlereagh also became unenthusiastic, as each day that put distance between the British Parliament and a real military emergency, increased its reluctance to have anything further to do with obligations to intervene in defence of a general European agreement. He dared not risk what President Wilson was later to do, knowing more certainly what his fate would be. Since there was to be no treaty of General Guarantee and no one really believed in the efficacy of the Holy Alliance, something else was required.

What eventually happened was the codification of the new piece of the diplomatic machine that we have seen coming into existence(15) . The pre-existence of its development made possible the implementation of the wishes of the powers: the system became the message and the significance of an historical development became crucial. It was not called into being by the demands of the moment - that path had been attempted but failed - and the character of its origin shaped the nineteenth century international system in profound ways, most particularly by stressing the practical and consensual over the application of rigid principle.

We may thus conclude that in at least two ways understanding the significance of historical development leads to a clearer vision of why we have what we have, and, perhaps, how it may be expected to evolve. Looking at the present and likely evolution in the immediate future, we can identify at least two significant developments. They both arise out of the changing nature and increasing numbers of principals in the global system. The complexities that these introduce can be listed: the spectrum of power, size and efficiency among states has widened sharply and produced a parallel widening in the range of the activities about which they may wish to be represented. In turn this has affected the functioning of associations of states - the most usual form of international organisations - who have discovered limits to the effectiveness of bi-lateral relationships. The recent difficulties encountered by the IMF in dealing with the financial crisis in Asia is a clear example of this. If both states and associations of states have experienced baffling complications and loss of power in their global dealings, the role of private, usually humanitarian organisations has sharply increased in significance, chiefly because the major crises in global politics are being caused by semi- or complete collapse of weak state structures. The consequences are unlike the previous patterns of international politics and have not proved amenable to traditional systems of control. They have instead induced the participation of large numbers of private organisations, with no tradition of self representation and little machinery for achieving it. Indeed, in so far as having to join the diplomatic nexus means joining the world of states, there can be an element of reluctance involved: fear of the ‘poacher turned gamekeeper’ syndrome. However, all the signs are that this reluctance is being overcome. Private organisations are developing their own diplomacy both between themselves and between actors in the state system; and the way they have been doing it is remarkably reminiscent of the early days of state self representation. The decisions of the UN to avoid bilateral compulsions by adopting coordinating status in humanitarian crises and to give recognition to greatly increased numbers of private organisations have provided another example of how existing parts of the diplomatic system can provide the means of responding to the needs of the current situation and to some degree actually shape them.