To second what Riverripper said... If you are interested in working abroad. If you are targetting American companies, go to a US school. A lot of American multinational companies recruit from within the USA and then send their employees abroad (will probably have to work in the USA first before being transferred), the MBA culture is within the USA For Example, a lot of internship programs are only available in the USA and are not available outside because the USA is so MBA focused. Internships around the rest of the world (outside of Banking and Consulting) is rarer and only some multinationals do this (e.g. Johnson & Johnson).
In terms of finding work internationally straight out of an MBA, then you are better being based in the region in which you wish to find employment (outside of Consulting and Finance). Even the top US schools have a sphere of influence around the areas they are strongest and weaken when you travel further from this location based sphere (e.g. West coast schools predominantly place in the West Coast, etc.).