The opening stanza of the Marine Corps hymn is: “From the Halls of Montezuma to the shores of Tripoli, we fight our country’s battles in the air, on land and sea.”

The “Halls of Montezuma” refers to the assault on Chapultepec Castle during the Mexican War, which was led by the small Marine contingent in Gen. Winfield Scott’s army. Ninety percent of the officers and NCOs who led the assault were killed.

The red stripe on the dress uniform trousers of Marine officers is in commemoration of the blood their predecessors shed that day. (For those who love historical coincidences, the Marines attacked along a route up the mountain that had been picked out by an Army engineer, Major Robert E. Lee. Immediately behind the Marines was a company of soldiers led by Lt. Ulysses S. Grant.)

“To the shores of Tripoli” refers to the Marine role in Thomas Jefferson’s war against the Barbary pirates. The “Barbary Coast” was a collection of Muslim mini-states on Africa’s Mediterranean coast stretching from present-day Algeria to present-day Libya. The principal source of revenue for the Barbary states was attacking shipping in the Mediterranean, stealing their cargoes and holding the crews for ransom or selling them into slavery.

The European powers of the day thought it cheaper to pay tribute to the Barbary states than to attack the pirates, and in 1784, the U.S. Congress followed suit. This was opposed by Mr. Jefferson, then the minister to France, who thought paying tribute would lead to larger demands. “It will be more easy to raise ships and men to fight these pirates into reason, than money to bribe them,” Mr. Jefferson wrote in a letter to the president of Yale University in 1786.

Thomas Jefferson favored forming an international coalition to fight the pirates, but the Europeans wouldn’t go along. When he became president in 1801, Mr. Jefferson refused Tripoli’s demands for an immediate payment of $225,000, whereupon the pasha of Tripoli declared war on the United States. This turned out to be a big mistake for the pasha. President Jefferson dispatched naval forces to the Mediterranean, and sent one of the most remarkable of American heroes, William Eaton, to Egypt to raise an army to attack Tripoli.

The only Americans Capt. Eaton had with him were seven Marines led by Lt. Presley O’Bannon. Mr. Eaton led the seven Marines and a motley force of about 500 Arab and Greek mercenaries on a 500-mile trek across the Libyan desert to attack Derne, Tripoli, which was captured in large part because of the reckless courage displayed by Lt. O’Bannon and his Marines. The dress sword Marine officers carry is modeled on the Mameluke sword an Arab prince presented to Lt. O’Bannon after the victory.

American naval forces commanded by Commodore Edward Preble and Capt. Stephen Decatur had successes against the other Barbary states. In 1805, President Jefferson told Congress the threat posed by the Barbary pirates was at an end.

Seizures of U.S.-flagged ships on the high seas have been few and far between since Jefferson’s time, thanks largely to his forceful response — until last week, when Somali pirates seized the aid ship Maersk Alabama. The crew recaptured it, but at this writing, the surviving pirates still hold the ship’s captain.

Piracy is thriving along the Somali coast today for the same reason it flourished along the Barbary Coast for 300 years. “The number of successful pirate attacks has increased almost fourfold since 2007, after the pirates received several multimillion-dollar ransom payments in early 2008,” the Intelligence Community said in its 2009 threat assessment.

The only effective way to deal with pirates is to kill them, as Thomas Jefferson did with the Barbary pirates, and the Royal Navy did a century earlier with the pirates of the Caribbean. The U.S. military has plans for dealing with the pirates, which need only the president’s approval to be put into action. The crew of the Maersk Alabama has passed its test. Will President Barack Obama pass his?