Robert Gilpin, War and Change in World Politics (1981), on the difficulty of retreat:

The fundamental problem with a policy of appeasement and accommodation is to find a way to pursue it that does not lead to continuing deterioration in a state's prestige and international position. Retrenchment by its very nature is an indication of relative weakness and declining power, and thus retrenchment can have a deteriorating effect on relations with allies and rivals. Sensing the decline of their protector, allies try to obtain the best deal they can from the rising master of the system. Rivals are stimulated to "close in," and frequently they precipitate a conflict in the process. Thus World War I began as a conflict between Russia and Austria over the disposition over the remains of the retreating Ottoman Empire (Hawtrey, 1952, pp. 75-81).

Because retrenchment signals waning power, a state seldom retrenches or makes concessions on its own initiative. Yet, not to retrench voluntarily and then to retrench in response to threats or military defeat means an even more severe loss of prestige and weakening of one's diplomatic standing. As a consequence of such defeats, allies defect to the victorious party, opponents press their advantage, and the retrenching society itself becomes demoralized. Moreover, if the forced retrenchment involves the loss of a "vital interest," then the security and integrity of the state are placed in jeopardy. For these reasons, retrenchment is a hazardous course for a state; it is a course seldom pursued by a declining power.

Gilpin goes on to describe a successful example of retreat: Great Britain towards the end of the 19th century. In order to focus on the threat of German naval expansion, Britain resolved its issues with the US, Japan, France, and Russia.