Dictatorship nations are outlaws. Any free nation had the right to invade Nazi Germany and, today, has the right to invade Soviet Russia, Cuba, or any other slave pen. Whether a free nation chooses to do so or not is a matter of its own self-interest, not of respect for the nonexistent 'rights' of gang rulers. It is not a free nation's duty to liberate other nations at the price of self-sacrifice, but a free nation has the right to do it, when and if it so chooses.
Ayn Rand