After Britain's rise as an empire, it pursued an isolationist policy towards the European continent, not only trying not to directly participate in the internal disputes of the European continent, but also treating the European continent as a whole and a whole force outside Britain. What Britain has to do is to suppress the possibility of any rise of the European continent, mainly to keep the countries of the European continent in a competitive state, and at the same time to ensure the balance of power between the two sides and let the internal friction of the European continent run out, so that Britain does not have to worry about the rise of the European continent countries to challenge its own world hegemony. Therefore, the core of Britain's mainland policy is to maintain the balance of power among the great powers in the European continent and avoid the rise of any country in the European continent, that is, "a powerful or dominant tyrant" as Churchill emphasized. If France becomes a powerful force, Britain will be pro-German and anti-French.

Isolationism has a profound influence in Britain (it has been clearly manifested until now), and it has further developed into the anti-war doctrine of the British nation. Anti-war doctrine has become an important psychological reason for appeasement policy. The policy of appeasement is that Britain and France try to satisfy Hitler's ambition at the expense of the interests of small countries, and fantasize that Hitler will stop aggression and get the peace he dreams of after gaining certain benefits, plus the deterrence of Britain and France. When the Germans attacked Poland, the British and French allied forces stood by in the trenches, which not only delayed the fighters, but also gave Hitler more time for military expansion. The appeasement policy is undoubtedly a daydream of Britain.