The general idea of a cadetship is that they are designed for those with little to no flying experience. For those with a license already, they must go through the direct entry process.
Except in specific circumstances, you can't fly for a foreign airline with your FAA license. For most other countries you will have to convert your license to that country first. The conversion process usually involves some theory exams, a bit of remedial training and a flight test. At least you won't need to repeat all the hours you've already done - they are credited anywhere.
The other part to consider is having the right to work in the foreign country. In places like Europe it will be difficult to get an airline to sponsor you because they already have so many local pilots they need to employ first. But it's easier in places like the UAE, Hong Kong and Singapore to name a few.