Because you believe that you have the right to intervene anywhere in the world whenever your interests are perceived to be threatened. The combination of such self-centered view and proclaimed right based on own perceived importance is among the top 10 reasons everyone loves the US.

The "rest of the world" can't have it both ways. The U.S. was heavily criticized (with some good reason) for not getting involved much earlier in WW II,when Hitler started his run on Europe.