When James K. Polk got his declaration of war as Mexico had "shed American blood upon the American soil," Rep. Abraham Lincoln demanded to know the exact spot where it had happened.
And did the Spanish really blow up the battleship Maine in Havana Harbor, the casus belli for the Spanish-American War?
The Gulf of Tonkin Incident, involving U.S. destroyers Maddox and C. Turner Joy, remains in dispute. But charges that North Vietnamese patrol boats had attacked U.S. warships on the high seas led to the 1964 resolution authorizing the war in Vietnam.
In 2003, Americans were stampeded into backing an invasion of Iraq because Saddam Hussein had allegedly been complicit in 9/11, had weapons of mass destruction and was able to douse our East Coast with anthrax.
"(He) lied us into war because he did not have the political courage to lead us into it," said Rep. Clare Luce of Franklin D. Roosevelt, who, according to many historians, made efforts to provoke German subs into attacking U.S. warships and bring us into the European war through the "back door" of a war with Japan.
This week marks the 75th anniversary of World War II, as last month marked the 100th anniversary of World War I.
Thus, it is a good time for Eugene Windchy's "Twelve American Wars: Nine of Them Avoidable." A compelling chapter in this new book, by the author of "Tonkin Gulf," deals with how Winston Churchill, First Lord of the Admiralty, schemed to drag America into Britain's war in 1915.
In 1907, Britain launched the Lusitania, "the greyhound of the sea," the fastest passenger ship afloat. In 1913, Churchill called in the head of Cunard and said Lusitania would have to be refitted for a war he predicted would break out in September 1914.
The Lusitania, writes Windchy, was "refitted as a cargo ship with hidden compartments to hold shells and other munitions. By all accounts there were installed revolving gun mounts."
On Aug. 4, 1914, after war was declared, Lusitania went back into dry dock. More space was provided for cargo, and the vessel was now carried on Cunard's books as "an auxiliary cruiser."
Churchill visited the ship in dry dock and referred to Lusitania as "just another 45,000 tons of live bait."
When war began, German submarine captains, to save torpedoes, would surface and permit the crews of cargo ships to scramble into lifeboats, and then they would plant bombs or use gunfire to sink the vessels.