Kupchan never mentions a common currency as a condition of comity among nations; in fact, economic integration tends to follow, rather than precede, achievement of political unity. Rather, he regards diplomatic engagement as the essential element to strategic accommodation and mutual trust, and this is more easily accomplished if the states have similar social orders and ethnicities.
库普乾并没有提及共同货币是国家间友好的条件；事实上，经济一体化总是在政治联合之后（而不是之前）才出现的。库普乾认为，外交才是战略融合和互信的基本要素，而具有相似社会秩序和民族成分的国家间更容易建立和谐的外交关系。