The Associated Press reports: U.S. officials say the Pentagon is moving two warships to the Libyan coast, in the aftermath of the attack in Benghazi that killed the U.S. ambassador and three others.

Officials say one destroyer, the USS Laboon, moved to a position off the coast Wednesday, and the USS McFaul is en route and should be stationed off the coast within days. The officials say the ships, which carry Tomahawk missiles, do not have a specific mission. But they give commanders flexibility to respond to any mission ordered by the president.

The destroyers have crews totaling about 300. There have been four destroyers in the Mediterranean for some time. These moves will increase that to five.

I guess this is the obligatory show of force that is inevitable after an event such as this. Even so, it seems reasonable to ask: if the presence of U.S. warships off the coast of Libya now serves a useful purpose, what difference would it have made had these ships already been in position two days ago? Almost certainly, none.