The reason as to the question about this comment "these foreign carriers" is because to group the rest of the worlds carrier into one neat group is just not practical, standards vary a LOT from country to country and even from different companies within that country. It is impossible to give you a yes or no answer.
I guess that the best I can do is tell you that in the rest of the industrialized world, airlines have similar and in some cases, more stringent hiring criteria that airlines here in the US, drug testing is pretty much a standard practice in most airlines but the testing is done along with the medicals (even if they tell you that they don't when you ask) as to background checks, also in most cases a criminal and professional background check is preformed.
Haven said that, worldwide there is every kind of different standards under the sun, there are very professional and structured airlines but there are also your shady operators. Not sure as to how else to answer that question???