冷战结束后，美国的军事实力发生了显著的变化。其军事战略先后经历了从“全球遏制”向地区防务、预防性防务、全球反恐、亚太地区再平衡等战略变化。在此过程中，美国军事实力的其他要素如国防费、兵力及武器装备等，也发生了相应的变化。在冷战结束后第一个十年的大部分时间里，美国的国防费、兵力和武器装备大幅削减。进入新世纪，特别是“9·11”事件之后，美国的国防费大幅攀升，兵力也在一定程度上扩大，新式武器的研制、开发与采购趋于活跃。上述变化对美国军事实力的另一构成要素——海外军事存在，产生了深刻的影响。
After the end of the Cold War,significant changes have taken place in U.S. military strength. Its military strategy has gone through changes from "containment" to the regional defense,preventive defense,global anti-terrorism,rebalancing toward the Asia-Pacific region. In this process,other elements of U.S. military strength such as defense expenditure,army scale, weapons and equipment also changed. During the first ten years of post-Cold War,it has seen a slash in U.S. defense expenditure,army scale, weapons and equipment. Entering the new century,especially after September 11,U.S. defense expenditure rose sharply. The army has expanded to a certain extent,and the development of new weapons has become active. Those changes have brought about a profound influence on the other element of U.S. military strength-military presence abroad.
