"You can send a man to Congress but you can't make him think," quipped comedian Milton Berle in the 1950s. To update Berle for our times: You can spend $60 billion a year on intelligence agencies but you can't make politicians read their reports. Instead, most politicians remain incorrigibly ignorant and hopelessly craven when presidents drag America into new foreign fiascos.

Congressional docility has been paving the way to war since at least the Vietnam era. In 1964, President Lyndon Johnson invoked an alleged North Vietnamese attack on a U.S. destroyer in the Gulf of Tonkin to ram a resolution through Congress giving LBJ unlimited authority to attack North Vietnam. LBJ had decided earlier that year to attack North Vietnam to boost his reelection campaign. The Pentagon and White House quickly recognized that the core allegations behind the Gulf of Tonkin resolution were false but exploited them to sanctify the war.

When the official story of the Gulf of Tonkin attacks begin unraveling at secret 1968 Senate hearings, Defense Secretary Robert McNamara proclaimed that it was "inconceivable that anyone even remotely familiar with our society and system of government could suspect the existence of a conspiracy" to take America to war on false pretenses. But indignation was no substitute for hard facts. Sen. Frank Church (D-ID) declared, "In a democracy you cannot expect the people, whose sons are being killed and who will be killed, to exercise their judgment if the truth is concealed from them." The chairman of the committee, Sen. J. William Fulbright (D-AR), declared that if senators did not oppose the war at that point,  "We are just a useless appendix on the governmental structure." But other senators blocked the release of a staff report on the lies behind the Gulf of Tonkin incident that propelled a war that was killing 400 American troops a week. Sen. Mike Mansfield (D-MT) warned, "You will give people who are not interested in facts a chance to exploit them and to magnify them out of all proportion." The same presumption has shielded every subsequent U.S. military debacle.