You can't assume that every country that has members of the armed forces in it has a military base. For example, many US embassies are protected by Marines. This is, IMHO, a perfectly legitimate use of the military overseas. Contracting or otherwise providing that security privately would be vastly more expensive, and adding a 'security' wing to the State Department is simply not an option.
Those who oppose American Empire building should not use the numbers of 'bases' or quantity of countries 'occupied' as their statistics of choice. The problem isn't the countries with 1, 4, 10, etc. military personnel. Rather, it's the large basings: Germany, Italy, Japan, etc. that need to be addressed.