Israel is following the "Powell Doctrine"

In 2001, an interesting event occurred in Gaza:

On April 17 (2001), Israeli military forces, after what was described in the press as fierce bombardment of Palestinian security positions in Gaza, took control of a square mile of territory in the Gaza Strip (territory that had been transferred to Palestinian control pursuant to the 1993 Oslo accords) and announced plans to hold it indefinitely as a buffer zone. The Israeli action was in response to a Palestinian mortar attack on Sederot, a town in Israel about four miles from the border with Gaza. The Israeli government explained its action as part of its ongoing effort to defend Israel from Palestinian violence.

United States Secretary of State Colin Powell issued a statement that said in part, "The hostilities last night in Gaza were precipitated by the provocative Palestinian mortar attacks on Israel. The Israeli response was excessive and disproportionate. We call upon both sides to respect the agreements they've signed." Shortly after Secretary Powell's statement was issued, the Israeli army announced that it was withdrawing from its positions in Gaza. The army withdrew, though it returned for 45 minutes the next day and destroyed a police station. The Israeli government denied that it had yielded to U.S. pressure to withdraw, but Israeli state radio and some others said the withdrawal was a response to U.S. pressure.

Powell's response at the time was a bit ironic.

Ten years earlier, in 1991, Colin Powell, the chairman of the Joint Chiefs of Staff, articulated the US policy for getting involved in conflicts. Powell used this initially to justify the first Iraq war. This became known as the Powell Doctrine, and it is most interesting to revisit during Operation Cast Lead.

The doctrine is summarized as follows:

1) Military action should be used only as a last resort and only if there is a clear risk to national security by the intended target;
2) The force, when used, should be overwhelming and disproportionate to the force used by the enemy;
3) There must be strong support for the campaign by the general public; and
4) There must be a clear exit strategy from the conflict in which the military is engaged.

Perhaps the Powell Doctrine didn't apply to Israel in 2001, as that was the very start of the mortar and rocket attacks towards Israeli towns in the Negev and massive force may not have yet been considered a "last resort."

But while we do not yet know Israel's exit strategy, the first three points are exactly in line with what Israel is doing today. Israel already tried truces, diplomacy, "soft" persuasion, and very limited military action to no avail, and in fact over time the rocket attacks only got more serious - and everyone in Israel realizes that the status quo was wholly unacceptable.

Most notable is the second point, where the Powell doctrine states that disproportionate force is not only not discouraged, it is required!

I have not yet seen anyone try to argue that the Powell doctrine is illegal under international law even though it explicitly states that the force used must be disproportionate. It must be one of those international laws that are only selectively invoked, for a single nation.