U.S. influence abroad, soft and hard, is the proverbial guard dog for the integrity of the global economy and international security. Lack of our presence will likely end in an increase in conflict, which, as I'm sure I don't need to point out, would result in negative effects on our economy. For example, let's take the regional animosity between China and India. Generally, U.S. diplomacy on both sides acts as a coolant between these two actors, especially since they're both vying for regional supremacy. Imagine if we didn't have a substantial presence in the region, and our viewpoints thusly became moot. The likely hood of conflict increases significantly, and is in fact almost 100% likely to occur. A war in that area of the world would be devastating. And that's just one example. There exist a dozen or so potential conflicts abroad that threaten the international security. Non-proliferation; terrorism; peacekeeping; etc. The problem is that what happens in one place of world directly affects us.

I love these internet armchair politicians.