When the cold war ended, nato used by shifting its focus from preventing russia from invading western europe to creating "rapid response forces" to combat terrorism and "rogue nations."?

The answer is goal displacement. This is first noted by Robert Michels in a research of the German Social Democratic Party. Goal displacement is the exchange by an organization of the objectives which it was recognized to serve, for other goals. The latter normally serve the benefits of employees. 

The tried to make the government smaller by making the government smaller