Thaksin Shinawatra, the prime minister of Thailand from 2001 to 2006, said, “I’m very disappointed by the mature-democracy countries. I was ousted by a coup d’etat.”

Yesterday, we looked at the Deschapelles Coup. Here is its cousin. South is in three no-trump, and West leads his fourth-highest spade. What happens after that?

North opened with a weak two-bid. South used the artificial two-no-trump inquiry and learned that his partner had a maximum with a feature (usually the ace or king) in hearts.

In no-trump, one typically returns partner’s lead as quickly as possible. Here, though, if East wins with his spade ace and plays a second spade, South takes the trick, drives out the diamond ace, and has nine winners: two spades, one heart, five diamonds and one club.

East must get the heart ace off the board so that declarer cannot establish and run the diamonds. At trick two, East must shift to the heart king.

South wins with dummy’s ace and plays on diamonds. East just holds up his ace for two rounds. (West’s two is surely a singleton; with a doubleton, he would play high-low.) Then South has no resource.

This is called a Merrimac Coup, named after the American steamship Merrimac, which was sunk in the entrance to Santiago de Cuba harbor in 1898 during the Spanish-American War in an attempt to bottle up the Spanish fleet.

Finally, note that the coup works even if West had started with king-jack-fifth of spades.