As a general heuristic, in modern warfare, countermeasures seem not to be very reliable. If you have to rely on countermeasures working perfectly for your mission profile, you're probably doing things wrong.
That's not to say they can't help you win, but even if it seems that they are perfectly effective history shows that they generally aren't.
That's not to say they can't help you win, but even if it seems that they are perfectly effective history shows that they generally aren't.