Sir Peter was probably Britain's last Field Marshal. The rank has been abolished in "peacetime" - and there will be no more "wartime", because there will be no more big wars. Let us hope so, anyway. Instead, we face a world of continuous engagement: in our own internal security problems - Northern Ireland; in peace-keeping - Bosnia and, possibly, Zaire; and in peace enforcement and limited war - as in the Gulf. But although a third of the Army is on active service (preparing to go or recovering afterwards), paradoxically it is the Army's fast-moving, armoured cutting edge that is looking vulnerable.
Defence is not an election issue. Yet there are huge issues to be addressed. As we enter the 21st century, we are grappling with the prospect of cyber- warfare (to which our information-based society becomes more vulnerable every day), with changes in the role and status of the nation state, and the possibility that missiles fired from the Middle East may soon reach us.
But, continually pressed for resources, military planners are also having to face the biggest defence choice in 90 years. Should we give up our commitment to high-intensity continental land war, a commitment shouldered in 1907? The next government will have to make some fundamental choices on Britain's military posture in the world. That is not going to be easy.
The Labour Party has criticised the Government for not spending enough, placing the "defence of the realm" at risk and leaving a massive hole in the defence budget, which is likely to become critical in around 2003. So you might think that, given the chance, Labour would actually spend more on defence. Clearly, they will not. Major defence projects - the last to be announced was the purchase of three new nuclear submarines, costing pounds 2bn - are always counted in billions. That would buy an awful lot of hospitals, and pay an awful lot of teachers.
The MoD's cash plans currently envisage spending about pounds 22bn a year. MoD officials privately believe the next Chancellor will want pounds 3bn from defence for other, more immediately pressing purposes - reducing this year's budget to pounds 19bn, or pounds 18bn after receipts from the sale of married quarters are taken into account. To achieve that, something big has to go.
Labour has committed itself to a strategic defence review, designed to look at exactly what tasks we are trying to do and what forces we need to do them. The plan is to complete it within six months of initiating the review in order to minimise disruption to the forces, which, any senior officer or civil servant will tell you, desperately need a period of stability. In practice, there will be unease and instability even before the review starts - there is now. So, as a wise man said, "that thou doest, do quickly".
The government has recently published the first-ever British Defence Doctrine (Joint Warfare Publication 0-01), an "overarching" document setting out the British view on the nature of war and armed conflict and what the armed forces are about. It was the product of a conscious decision, which goes back to the mid-Eighties, to intellectualise the way we think about these things. But the exact timing of its release was clearly designed tip pre-empt Labour's strategic defence review. "Why would we need a strategic defence review? We've done one. Here it is."
What if Labour's strategic review finds that JWP 0-01 has got the conceptual framework right? Would a new Labour government, six months or so into its new term, accept that? Probably not.
And suppose Labour's review decided that we were right to carry on doing everything we do now. The defence budget is infinitely susceptible to creative accounting, but there is certainly a pounds 300m hole in it at the moment; and to be safe, it probably needs another pounds 500m a year to do everything it would like to on present plans. A true back-to-basics review might also conclude that we need Ballistic Missile Defence: an anti-missile missile system, to deal with the likely deployment of long-range missiles by unpredictable Middle Eastern potentates who are not susceptible to deterrence. And that we need to reduce the vulnerability of our entire information-based society to cyber-war waged on the Internet. To do all that would mean raising the defence budget by another billion a year - pounds 1.5bn a year in all. Would a future government do that?
Clearly, therefore, something has to go. Of the three services, the Air Force looks relatively secure. The overwhelming dominance of air power in any operations and the industrial consequences of pulling out of major aircraft and missile projects make that option unattractive - particularly to Labour.
Given the changes in Europe since the end of the Cold War, and the disappearance of the threat of a land invasion, senior military planners are now having to think the unthinkable. The maintenance of an armoured division in Europe, and the associated ability to fight first-division land battles would have to be sacrificed. Either that, or a large chunk of the Navy (or of the Air Force.)
The good news is that Britain is most unlikely to have to undertake a military operation alone. Just about every forseeable future war would be fought by a coalition. Theoretically, therefore, individual nations in Nato could specialise. The Navy, understandably, believes that as an island we should specialise in things maritime and leave driving tanks around Germany to people like the Germans. We will need soldiers for internal security and international peace-keeping. But do we now need that 25,000- strong armoured division as the core of a top-of-the-range continental land army?
The snag in this argument is that, at the moment, the Navy is not fighting anybody, or standing on street corners making sure they behave themselves. The Army is.
Most of the 17,000 troops in Northern Ireland and of the 5,300 in Bosnia come from bases in Germany. Merely pulling 25,000 troops and their families out of Germany would not save very much money: in fact, it would probably cost money as new accommodation would have to be built in Britain. Land for training in Britain is already tight: the Army would like 85,000 acres more, though it will not get it. As weapons get bigger and fire further - the range of artillery has doubled in 20 years - training land is a real problem. The Army's best hope, apart from increased use of simulators , is new training land in Poland and Ukraine - which is much easier (and cheaper) - to get to from Germany.
The only way of saving a significant amount of money would be to ditch the lot. What is at issue is therefore nothing less than the relegation of the British Army to the second division. To a peace-keeping-only Army, like the Canadian or the Irish.
Senior officers are unanimous that there is a certain critical mass below which you cannot go, a certain group of skills you must have to be a serious Army. Tanks, artillery, armoured infantry, attack helicopters, anti-aircraft and anti-tank missiles, command, control, communications and intelligence. The Army does not believe it could, for example, do away with Main Battle tanks - the 60-ton Challengers - without breaking up that carefully balanced cocktail.
Soldiers point to the experience of Bosnia. The British were highly effective in a complex, "wider peace-keeping" operation, because they came equipped for war. When the peace implementation force arrived in December 1995, the deterrent effect of heavy artillery and tanks which were twice as big as any the local parties had seen was remarkable.
As the threat from Germany grew before 1914, the General Staff called for a continental system of conscription and an Army of half a million to fight in Europe. They did not get it; but from 1907 they got a first- rate modern army - the British Expeditionary Force. At first, it was thought the BEF was as likely to go to Afghanistan as to Belgium, but from 1911 it became the core of Britain"s "continental commitment".
Britain has endeavoured to maintain an army of that kind ever since. Running Nato's Rapid Reaction Corps and providing an armoured division is about the minimum you need to do that. The problem is that, at the moment, there is no specific role for it. However, the Army insists it has to remain at first division level because once it is relegated, it would take decades to get back. The ability to fight a "high intensity war" is a genie in a bottle - to be magicked out in a dimly foreseen time of dire need. Furthermore, an Army full of first division players can play and win a second division game. The converse is untrue.
Doing away with this ability would have other dire consequences. Since the mid-Eighties, the Army has poured a great deal of intellectual effort into studying the operational level of war - the handling of large forces - a newly recognised level between tactics and strategy. Do away with your first division Army, and your study of the operational level, which has played a great part in making British soldiers think, becomes merely academic.
But can any British government justify paying for an increasingly expensive first division force merely as an insurance policy and as an engine room to generate excellence in other fields? Foreign secretaries often say that Britain punches above its weight in world affairs. One reason is the excellent military forces it continues to maintain. Still, if the other spending ministries win the inevitable cabinet battle over spending, the choice for the forces will have narrowed down to that between a balanced Navy, or a first-class, high-intensity warfare Army. Reduce either, and you reduce Britain's role on the world stage. But if reduce we must, given our present commitments, the Army has the better case.