Is a buffer zone — such as the one that Israel is establishing in Lebanon — legal under international law?

The short answer is: possibly.

But the long answer is more complicated and, experts say, leads to the conclusion that what Israel is establishing in southern Lebanon may not actually be a "security buffer zone" at all, at least not under international law.

Since early March, Israeli troops have taken over an area of Lebanon between 5 and 10 kilometers (3 and 6 miles) away from the border. Israel has argued it is acting in self-defense. Prime Minister Benjamin Netanyahu says the buffer zone in southern Lebanon is to "thwart the threat of invasion" from the Lebanese militant group Hezbollah.

But is a buffer zone legal?