Governments lie.

Even more so when the issue is war.

“We will crush al-Qaeda,” Barack Obama insisted during the second presidential debate on Oct. 7, 2008. “That has to be our biggest national security priority.”

At various times, Obama has declared al-Qaeda to be “on the run,” “decimated” and “on their heels”. In Jan. 2014, he was quoted in a New Yorker article likening al-Qaeda to an ineffectual junior varsity team.

But just one week after ISIS carried out the Paris terrorist attacks, a group affiliated with al-Qaeda killed 20 people in Mali.

Then, in early December, al-Qaeda fighters seized two major cities in Yemen as part of its effort to expand its influence in the country.

So much for the collapse of al-Qaeda.

On multiple occasions Obama has also asserted that the last American troops in Afghanistan would return home by the end of his presidency, concluding the longest war in U.S. history. But fighting with the Taliban still rages.

On Dec. 21, a Taliban suicide bomber on a motorcycle slaughtered six American troops and injured two more near Bagram Air Field in Afghanistan. And American troops will still be there when Obama leaves office.

“With control of — or a significant presence in — roughly 30 percent of districts across the nation, according to Western and Afghan officials, the Taliban now holds more territory than in any year since 2001, when the puritanical Islamists were ousted from power after the 9/11 attacks,” the Washington Post reported today.

As Afghan security forces deal with over 7,000 dead and 12,000 injured in 2015,  U.S. Special Operations troops are increasingly being deployed into harm’s way to assist their Afghan counterparts, according to the Post.

But Obama still insists American troops aren’t at war in Afghanistan any more, just “training and advising”.

Of course, the Soviet government wasn’t exactly honest with its people when it sent troops into Afghanistan in 1979 either, or during its next 10 years of war there.

The Soviet Union sent over 100,000 soldiers to fight in Afghanistan, withdrawing only after at least 15,000 of its soldiers (and more than a million Afghans) had been killed.

Oral testimony from the Soviet soldiers reveals that during much of the war the Soviet government told its people little more than that their children were building hospitals and schools, helping the Afghans build a socialist state and “…bravely protecting the frontiers of the fatherland…in the execution of (their) international duty.”

In fact, there’s a long history of deception in American wars, too.

In 1898, President McKinley said the USS Maine had been sunk in Havana Harbor by a Spanish mine, killing 266 officers and enlisted men and justifying the Spanish-American War. It turned out burning coal in a bunker triggered an explosion in an adjacent space that contained ammunition.

Then there’s the U.S. war in Vietnam.

In 1964, President Johnson ordered retaliatory attacks against gunboats and supporting facilities in North Vietnam after attacks against U.S. destroyers in the Gulf of Tonkin.

Spurred on by Johnson, the U.S. Senate passed the Gulf of Tonkin Resolution authorizing the president “to take all necessary measures to repel any armed attack against the forces of the United States and to prevent further aggression.” Only two Senators, Wayne Morse of Oregon and Ernest Gruening of Alaska, voted “no”.

But reports of the attacks were a lie, as were so many reports on the progress of the war in subsequent years and incursions into Laos and Cambodia.

And so began the tragedy known as the Vietnam War.

David Halberstam wrote an often-cited book “The Best and the Brightest” about the overconfident, foolish people who pursued the war.

“The basic question behind the book,” he said later, “was why men who were said to be the ablest to serve in government this century had been the architects of what struck me as likely to be the worst tragedy since the Civil War.” (The term “Best and the brightest “ has often been twisted since then to mean the top, smart people, the opposite of Halberstam’s original meaning)

Years later, Daniel Ellsberg, who made the explosive Pentagon Papers public, said, “The Pentagon Papers…proved that the government had long lied to the country. Indeed, the papers revealed a policy of concealment and quite deliberate deception from the Truman administration onward.”

And then, of course, there were the “weapons of mass destruction” in Iraq.

“We know that Saddam Hussein is determined to keep his weapons of mass destruction, is determined to make more,” U.S. Secretary of State Colin Powell told the United Nations on Feb. 5, 2003. “…should we take the risk that he will not someday use these weapons at a time and a place and in a manner of his choosing, at a time when the world is in a much weaker position to respond? The United States will not and cannot run that risk for the American people.”

And so the war began.

As columnist Sydney Schanberg wrote, “We Americans are the ultimate innocents. We are forever desperate to believe that this time the government is telling us the truth.”