Because it's the pilot who makes the choice. Intentionally going to a foreign country without the appropriate documents is a bad idea with unpredictable consequ

Because it's the pilot who makes the choice. Intentionally going to a foreign country without the appropriate documents is a bad idea with unpredictable consequences. Unless the destination country gives legally binding guarantees that nothing bad is going to happen, it's not something a reasonable person is going to do. Especially for a trivial reason such as work.