The best part of the foreign policy debate occurred when Mitt Romney hit the president for maintaining a Navy that is smaller than the number of boats afloat in 1917.

Obama’s zinger about the shift from “horses and bayonets” and the rise of “aircraft carriers, where planes land on them, and ships that go underwater, nuclear submarines” was a winner. He told Romney the “question is not a game of Battleship, where we're counting ships. It's what are our capabilities.”

The Wall Street Journal today gamely tried to defend Romney’s naval build-up, turning to his naval advisor John Lehman to critique President Obama’s contention that the current 287 ship U.S. Navy is big enough to deal with current and emerging threats.

It was an odd choice. While Secretary of the Navy under Ronald Reagan, Lehman advocated The Gipper’s proposal for a 600-member naval fleet as part of the massive military spending to bankrupt the Soviet Union and end the Cold War. Reagan never got all his boats. And Lehman apparently has a new religion. He now says Romney’s goal of 350 boats is just fine. That’s a 250 boat differential than what he proposed during the 1980s, which makes Obama’s case that we don’t the same size fleet that America had 95 years ago due to improved capabilities, range and firepower in a changing world.

For the record: Obama has proposed a fleet of more than 300 ships. The current fleet is bigger than the all-time low of 278 in 2007 when George W. Bush was in power. The Navy just christened the USS America, a first of a new class of amphibious assault carriers. It costs $2.5B. The U.S. Navy today is bigger than the next 13 combined navies.

As for those bayonets, the president was wrong to dismiss them as outdated. The Marine Corps currently has more than 175K bayonets. Captain Kendra Motz told the New York Times: “Basically, when you’re in a hand-to-hand combat situation, if you’re out of ammo and if your rifle malfunctions you can attach the bayonet and still kill somebody.”

Some things never change. A bayonet is as useful today as it was during WWI.