In the coming weeks, both chambers of Congress are expected to debate and vote on a bill repealing the authority that Congress gave President George W. Bush to use force against Iraq.

It has been more than half a century since Congress repealed a similar resolution. That was the Gulf of Tonkin Resolution of 1964, which had allowed then-President Lyndon Johnson to escalate the conflict in Vietnam.

That war ultimately cost more than 55,000 American lives and many times that many Vietnamese lives, destabilizing the entire region.

We will return to that precedent in a moment. For now, Congress is focused on the fallout from its decision to greenlight a war with Iraq in October 2002. The U.S. and its allies invaded and occupied Iraq the following March. It was 20 years ago this month.

The Senate eyes a formal end to the Iraq War, and a reassertion of Congress' power

There was no declaration of war against Iraq, although the Constitution gave that power to Congress in its Article I. Congress has not declared war on anyone since 1942, nor has any president asked it to. But there have been long and bloody wars in Korea, Vietnam, Afghanistan and Iraq – not to mention hundreds of strikes using drones, missiles and "special forces" (the exact number is not known).

By repealing its 2002 authorization for the war in Iraq, Congress may hope to reassert more control on the war-making decisions of the executive branch. That is the goal, at least, of many on Capitol Hill.

One of repeal's principal sponsors in the Senate is Virginia Democrat Tim Kaine. He says the 2002 authorization (and another granted to President George H.W. Bush in 1991 prior to the Persian Gulf War) "are no longer necessary, serve no operational purpose, and run the risk of potential misuse."

A struggle as old as the republic

Congress has tried to stand up to presidents in previous eras, as the struggle between the branches is built into the nation's founding documents. But Congress has been weakened in this struggle by events over a long period of time and more recently by dramatic events in real time.

Congress has often been complicit in allowing the executive leeway for military adventures, dating back at least to Thomas Jefferson's forays against pirates in the Mediterranean in the early 1800s.

But the expansion of presidential war-making accelerated literally in a flash on Sept. 11, 2001, when hijacked airliners smashed into the World Trade Center and the Pentagon. Nearly 3,000 lives were lost, exceeding even the death toll from the Japanese attack on Pearl Harbor that propelled the U.S. into World War II.

Sept. 11, 2001, galvanized Americans much as Pearl Harbor had. Americans were fearful, and also vengeful. The awfulness of the Twin Towers collapsing and the grief of thousands of families who lost loved ones turned swiftly to anger. There were popular songs on the radio and rants on TV about what the U.S. would do in retribution. Just three days after those attacks, Congress met and passed an authorization for the use of military force, or AUMF, directing President Bush to go after the perpetrators and those who harbored or enabled them.

That covered the invasion of Afghanistan that fall and has been used by every president since for scores of operations — many still secret. It is important to note that the 2001 AUMF against terrorists would remain intact under the current Senate's repeal bill; the measure would apply only to the later resolution aimed specifically at Iraq and an 1991 AUMF concerning Iraq's invasion and occupation of neighboring Kuwait.

Shifting the onus of Sept. 11 to Saddam

The Iraq resolution came 13 months after Sept. 11. The initial thrust into Afghanistan had ousted the Taliban regime but failed to capture al-Qaida leader Osama bin Laden. The Bush administration increasingly turned its attention to the regime of Saddam Hussein. While never explicitly saying Saddam had aided in the Sept. 11 attacks, Bush and his national security strongly implied it.

"Iraq continues to flaunt its hostility toward America and to support terror," Bush told Congress in January 2002. "... The Iraqi regime has plotted to develop anthrax, and nerve gas and nuclear weapons."

Bush also asked Congress to "imagine those 19 hijackers [on Sept. 11. 2001] with other weapons and other plans, this time armed by Saddam Hussein." Just before the AUMF of 2002 was debated, national security adviser Condoleezza Rice warned the U.S. could not wait to find "a smoking gun" because it might be "a mushroom cloud."

So the Iraq AUMF was approved by a vote of 296-133 in the House and 77-23 in the Senate. Only six Republicans voted no in the House and just one in the Senate. A majority of Democrats in the House were opposed (126-81). But in the Senate, the majority of Democrats voted yes (29-21). There was one Independent vote against the resolution in each chamber.

Tracing a familiar track with tragic results

In all this, the trajectory of the Iraq War as an issue in domestic politics tracked the precedent set by the Vietnam War.

Before the U.S. rolled into Baghdad 20 years ago, Iraqis warned us what would happen

The Tonkin Resolution was named for a bay on the Vietnamese coast where torpedo boats were alleged to have attacked U.S. warships. Johnson persuaded Congress the national honor was at stake and Vietnam was the key to stopping the advance of global communism. Congress passed a resolution saying he could "take all necessary measures" to protect U.S. interests in Vietnam. The House voted unanimously for it, and only two members of the Senate opposed it.

In 1970, the Senate vote to repeal it was 81-10. (The lopsided vote for Tonkin in 1964 was nearly matched by the vote for the September 2001 AUMF against terrorists, which had one House member, Democrat Barbara Lee of California, opposed and two senators not voting.)

Back in 1964, Johnson had his Tonkin authority and public support (he won a full term in the White House that November with 60% of the popular vote). Soon, he was escalating the war until half a million U.S. personnel were in Vietnam. Draft orders soared, protests proliferated, and support on Capitol Hill deteriorated.

Although popular at first, Johnson's war became an albatross. He aborted his bid for a second elected term in 1968.

Two years later, Johnson's Republican successor Richard Nixon was trying to wind down U.S. involvement in Vietnam and did not want to defend the Tonkin resolution. The leaders in both parties in Congress were ready to have it off the books so as to assert more oversight on presidential war-making.

Attempts in that direction were made in the years that followed, including the passage of the War Powers Resolution in 1973. But presidents continued to find ways around Capitol Hill in the decades to come, especially after the life-changing experience of Sept. 11, 2001.

The 2002 Iraq vote cast a long shadow on domestic politics

Any comparison to Vietnam seemed far-fetched when Congress went along with Bush on Iraq in 2002. The initial invasion was successful: Baghdad fell and the Iraqi dictator Saddam Hussein went into hiding (later to be captured, tried and executed).

But the occupation that followed was awkward at best, breeding far greater resistance among Iraqis than Bush administration planners had expected. Even those glad to be rid of Saddam chafed at the presence of a foreign army. presence.

Over time, support waned back at home, as well. The war paid the U.S. no visible dividends and made no new friends. Multiple polls measured support above 70% in the month of the invasion, but below 50% by the summer of 2004. It has remained under water ever since.

US Still Has Lessons To Learn From Its Misguided War In Iraq

While Bush survived to be reelected in 2004, he came close to losing in the Electoral College. He had the protection, too, of noting that his Democratic opponent John Kerry, a Democratic senator from Massachusetts, had voted for the Iraq authorization — as had Kerry's running mate John Edwards of North Carolina.

But two years later, Democrats stormed to majorities in both chambers of Congress in 2006 for the first time in 12 years. The central issue that year: the Iraq War.

Early in 2007, as debates began among Democratic candidates for president and first-term Sen. Barack Obama used his opposition to the Iraq War as an Illinois state legislator to set himself apart from more experienced Senate colleagues — especially putative frontrunner Hillary Clinton of New York.

More than a few observers at the time noted that without that Iraq vote, Obama would not have had an actual issue to use against Clinton.

Biden Tries To Clarify His Record On Iraq War During Democratic Debate

Just as Obama had made Clinton pay for her 2002 vote on Iraq, Trump used it to question her judgment in the 2016 fall campaign. Trump himself had expressed ambivalence about the Iraq War on several talk shows when it began, but he later claimed to have been against it before it even began. He has also later classed it among the "forever wars" the U.S. should never have fought.

Vermont Sen. Bernie Sanders, an independent running for president in 2016 and again in 2020, called the Iraq War "the worst foreign policy blunder in U.S. history." He himself had voted against the resolution in 2002 as a member of the House. But his effort to use the issue against Biden in the 2020 primaries was ultimately not successful.

As president, Biden has signaled the president would sign the repeal, which some in Congress have been pushing for years. The House passed a repeal bill in 2021 that did not get to the Senate floor. The sponsor of that House bill, as well as this year's successor version, was Democrat Barbara Lee of California.

Lee was the lone member of Congress to cast a vote against not only the 2002 Iraq resolution but also the previous AUMF against terrorists that cleared Congress three days after Sept. 11, 2001.