It's also worth noting that the since American military provides such a large security blanket to global trade that most nations who would otherwise tough it out themselves to protect their merchant fleets don't have to, unless they are are in piracy hotspots like Somalia. Many non-American merchant ships often fly the Stars and Stripes illegally to deter those who are averse to pissing off the US Navy.

America does often not like it when countries other than itself goes to war because it makes it hard to sell American consumer goods there, unless those goods are the weapons of war themselves.