What were the justifications for "appeasement" in terms of British domestic politics?

"He is a man I can do business with; he is a man I must do business with," Gerry Adams said after he emerged from a meeting with David Trimble in Stormont. These words could just as well have been used by Neville Chamberlain sixty years earlier to refer to his Munich discussions with Hitler; vastly different circumstances, but a desire by both men to avoid future conflict by coming to an agreement with those they were wary of for the good of the people they represented. Whether a deal will be done in Northern Ireland remains to be seen; the events of the months and years following Munich have been documented innumerable times. Although Chamberlain has ever since been criticised as the main proponent of appeasement - a policy which to some appears a ridiculous and unjustifiable cowering by a liberal democratic society to the threats posed by dictators in other countries. However, many armed conflicts arise seemingly without warning or prediction (e.g. the Falklands, the Gulf), and Chamberlain had, until Munich, every reason to attempt to avoid war in Europe. It was only when it became realised that Hitler would not cease when he had re acquired the Sudetenland that public and political opinion favoured preparation for war. At this time, Chamberlain became isolated in pursuing his peace strategy.
Perhaps the key motivation for avoiding war was the sorry state of the British armed forces, whose budgets had been slashed after the First World War to help pay off the large amounts of debt that this conflict had incurred. The Ten Year Rule of 1919 prepared budgets for the services based on the assumption that Britain would not be involved in any large-scale conflict in the following decade. Thus the defence spending which had stood at �766m in 1919-20 had fallen to just �102m in 1932. What had accounted for 3% of government expenditure in 1913, by 1933 stood at just over 10%. Following an agreement with the other naval powers in 1921, a cap was placed on naval construction for ten years, which had left Britain by the 1930s with a fleet of obsolete vessels that senior naval officers warned were no longer capable of defeating other naval powers; for the first time the Royal Navy could not be regarded as the superior naval force. This freeze was agreed in order to avoid an enormously expensive Anglo-American naval race that Britain couldn't possibly have won. The RAF had few modern aircraft (Spitfires and Hurricanes only arrived as the war broke out), and had no long-range strike capacity to attack targets in Germany; such missions, it was warned by the Chiefs of Staff, "might end in disaster." More disturbing than this was the perceived threat from the Luftwaffe, given Britain's lack of air defence fighters and radar network. It was feared that should Germany launch concerted attacks against Britain, there would be serious losses to life and property as a result; if occupied bases in Belgium and the Netherlands were used to launch these attacks, then not only the South of England was at risk, but most of the Midlands and the east coast were within range of these bases as well. As it turned out, these projections were excessively pessimistic and over-estimated the bombing skill of Luftwaffe pilots. However, the feeling at the time demonstrates that far from being a deterrent against the Germans, the RAF was actually deterred by them. Finally, there was the Army, which had been the worst treated of the three services. A sub-committee of the Imperial Defence Committee known as the Defence Requirements Committee was set up to draw up a programme for improving the condition of the Armed Forces. It's recommendations - the first proposals for seriously improving the condition of Britain's armed forces - were largely incorporated into the Defence White paper of 1936. However, the measure for creating a "Field Force" capable and willing to intervene on the Continent was blocked by the Cabinet on the grounds that the public would object to this being a similar venture to the Expeditionary Force that met with disaster in the First World War. In the end, the proposals for five front line divisions supported by twelve Territorial Army divisions weren't fulfilled; the five front line divisions were allocated funding, but weren't equipped for Continental intervention. The British order of battle was worsened by indecision from the Chiefs of Staff over exactly what resources they would require, and numerous about-turns as to what their objectives actually were.
This is understandable, however, given the entire range of world-wide assets that Britain had to defend in the form of her Empire. Germany was not the only potential enemy that Britain faced - Japan had become increasingly belligerent and aggressive in the Far East, a fact demonstrated by their invasion of Manchuria in 1931 and campaign against China throughout the build-up to the Second World War. Quite simply, Britain was in a "Catch-22" situation; it simply hadn't enough assets - especially naval ones - to maintain a competent defence in both the Mediterranean and the Far East at the same time. Unsurprisingly, Australia and New Zealand were more concerned with Japan than with Germany, but key Dominions like Singapore and Hong Kong were also at risk. The only way a counterweight to Japan could be provided would be to strip the Mediterranean of all British naval assets (which in any case were thinly spread and unprepared for a war with Germany), which could well induce Germany and/or Italy into commencing campaigns that the fleet was in the Mediterranean to prevent. On the other hand, the need to maintain a naval balance of power in Europe removed assets from defending locations such as Singapore, which had already suffered when the plans for a huge new naval base there had been scrapped. The Chiefs of Staff were terrified at the prospect of simultaneous wars against Japan, Germany, and Italy, which they realised they could never win, even with the support of France and Russia. Even if Britain was only to face a conflict on a single front, Imperial commitments would tie down a large portion of the British armed forces. All Dominions would need protection; Far East assets were vulnerable from Japan, European ones from Germany, Italy, or a combination of the two, and the general shortage was only exacerbated by the Italian success in capturing Abyssinia (now Ethiopia), which posed a new threat to Egypt. In addition to this, more troops were being sent to deal with unrest in Palestine. It was even perceived that nationalist elements in India would take advantage of a World War to stage a revolution. How, it was asked, could an under strength Army commit itself to all these theatres plus an extended campaign on mainland Europe? The defence of the Empire would require peace in Europe, which in turn would be achieved through appeasement. British defence policy was thus a gigantic and risky juggling act of preserving all its interests with under strength and overstretched military assets.
In a large part, this defence policy was determined by the Treasury. Before he succeeded Baldwin as Prime Minister, Chamberlain spent time as Chancellor, and understood the severity of Britain's economic problems. The First World War had increased national debt eleven fold, and in the 1920s, interest debt repayments were accounting for 40% of the government's expenditure. The economy went into a general decline after 1918, and the result of this was that there as no money available to improve the condition of the factories nor to undertake any major capital investments. Thus when money was eventually released for rearmament in the 1930s, there wasn't enough productive capacity in the economy to build up a supply of arms. There was also a massive shortage of skilled workers. Thus the traditional view that has portrayed the Treasury as an obstruction, appeasing, and responsible for military unpreparedness must be re-examined. A more modern and balanced view would assert that the Treasury could neither afford to order the goods necessary for rearmament, and that the economy could not produce them anyway. The Depression had increased the need for strict economic control; to engage in an arms race would force a move away from a balanced budget, and would jeopardise the revival in exports, as well as having a negative impact on the balance of payments situation, and leading to significantly higher inflation. The economic situation at the time of the Japanese invasion of Manchuria in 1931 involving the decline of sterling, being taken off the Gold Standard, and spiralling unemployment, help to explain why no action was taken - the economics were more pressing than committing to a conflict on the other side of the globe, which, in any case, Britain did not have the resources to fight. This lack of resources was alluded to by Chamberlain when, in a reply to a memo sent to him by the War Office complaining that to approve the five divisions of the Field Force without any reserves was illogical, he replied that there simply weren't enough national resources to provide for the Royal Navy, a powerful RAF, imperial commitments, the air defence of Britain, and a continental involvement by the Army.
There was also a distinct lack of support for another European war, both among the British population and other countries in the Empire. The "Never Again" mentality and revolt against the idea of war that began after the Armistice was still prevalent throughout the 1930s, and only began to change in the run-up to Munich, as Hitler's aggressive intentions became clearer. There was a need to carry public opinion behind any war effort, and to do so would require extensive re-education of the population as to the dangers that isolation would produce. Many people supported the goal of resolution through the League of Nations. However, it had become increasingly apparent that this organisation would and could not intervene in any way; it had done nothing over the invasions of Manchuria and Abyssinia. The idea of pooling armed forces was not reassuring, even given the state of the British forces; the notion of Argentinean, Portuguese, or Greek troops defeating Germany was not credible. Different reasons were behind hostility to war from some members of the Empire. Countries such as South Africa and Canada refused to commit themselves to fighting Germany simply on the grounds that Hitler had entered the Sudetenland - intervention against this was seen by these countries as "preventing certain Germans rejoining their Fatherland." In 1938, the Dominions Secretary, Malcolm MacDonald, warned that this was an issue on which the Commonwealth could "break in pieces." Thus when Chamberlain returned from Munich, the scenes of jubilation in the country at large were in no way staged. The only noteworthy opposition to the Munich treaty in the Empire came from New Zealand, and a small minority of Conservative MPs. Even the Chiefs of Staff and the Imperial Defence Committee supported Chamberlain's strategy; the postponement of war would enable Britain to build up her defences, possibly even to deterrent levels.
So we can see that there were many solid reasons for using appeasement to avoid Britain's involvement in one or many conflicts that, in the view of the Chiefs of Staff and politicians, she could not win. Appeasement was based on their desires to extricate the country, by diplomatic manoeuvre, from the prospect of a conflict against a combination of adversaries which in their professional judgement could not be successfully sustained. This was similar to the 1902-07 appeasement; however, the nations Britain was now facing were aggressive, predatory powers who viewed appeasement as a sign of weakness. A two-pronged defence strategy (involving both Home Defence and Imperial Defence) overrode the traditional British defence policy: that of assuring the European balance of power. Yet Britain did not possess the resources to pursue both strategies with maximum strength at the same time. This constraint naturally resulted in attempting to defuse the situation; however, the dilemma faced was a choice between two dangerous positions: plan for war at risk of causing serious damage to economy or continue in search for co-operation at the cost of increasing the strength of a potential enemy. That the latter option was followed reflected the fact that Britain was a satiated nation who simply wished to retain what she had, and to live in peace with her neighbours. This provided the rationale for support of the League of Nations. Just as in contemporary Northern Ireland, there was an imperative to "take risks for peace" and to make concessions to avoid greater conflicts. Britain had nothing to gain and everything to lose by precipitating a full-scale war. Appeasement was justified by the interaction between the factors of a poorly equipped military that had to provide a global defence for all of Britain's territories, an anti-war mindset among the population, and economic circumstances that pointed to the avoidance of a large-scale conflict. That Chamberlain pursued this strategy until it was abundantly clear that war was inevitable is proof that he understood thoroughly all the implications that a conflict would bring. Thus it is harsh to lambaste his policy of "try, try, try again" by which he attempted to secure "peace in our time."