(CNN) Was the decision to strike against terrorists in Afghanistan "wrong" in 2001 or should the US now just declare victory and leave?

These are two ideas floated by members of Congress about the war, now nearly 18 years long and counting, after it cost more than 2,400 American lives and wounded more than 20,000 US service members while causing exponentially more pain to Afghans without eliminating the Taliban

Both Democratic Rep. Alexandria Ocasio-Cortez of New York and Republican Sen. Rand Paul of Kentucky dislike the open-ended Authorization for Use of Military Force, known as the AUMF, that was approved after the Sept. 11, 2001, attacks. But while Ocasio-Cortez argued Tuesday that the fight in Afghanistan itself was a "wrong war," Paul and Sen. Tom Udall of New Mexico, a Democrat, want to declare victory and pay new bonuses to people who fought in it.

The divide is the latest sign that no one in American politics seems to know exactly how to move on from Afghanistan.

Which makes this an issue that could become part of the 2020 discussion, especially as the US grapples with how to deal with its continued presence in Syria, where President Donald Trump said he would remove troops, and in Afghanistan, where Barack Obama once said he was drawing down combat troops, where Trump has said he will draw down troops.

The freshman New York congresswoman tweeted Tuesday in defense of fellow Democratic Rep. Ilhan Omar of Minnesota, who is under fire over critical comments about congressional support for Israel, by noting that it was considered "unacceptable" to question US military engagements after 9/11.

"I remember a time when it was 'unacceptable' to question the Iraq War. All of Congress was wrong, including both GOP & Dem Party, and led my generation into a disastrous + wrong war that virtually all would come to regret, except for the one member who stood up: Barbara Lee."

Lee was the one vote in Congress against striking Afghanistan in the days after the terror attacks. Ocasio-Cortez later clarified in a tweet that she meant Afghanistan was the "disastrous + wrong war." But she said she feels that way about the Iraq War too.

These are two very different conflicts. A lot of Americans do think it was wrong to go into Iraq, which occurred after an attempt to build an international coalition based on flawed evidence delivered at the United Nations, and after a vote by a divided Congress.

Questioning the American war in Afghanistan is a much more controversial idea, however, especially for a lawmaker representing boroughs of New York City, where thousands of Americans died when planes struck the World Trade Center.

It was seven days after that event -- when the wreckage in lower Manhattan, at the Pentagon and in Pennsylvania was still smoldering -- that lawmakers voted to respond to the terror attacks by striking at al Qaeda and the Taliban in Afghanistan. They could not have known that almost 18 years later, the US government would still be using the same vote to fight the same war.

The unintended consequences of that vote are pretty clear. And the inability of Congress to debate and vote on subsequent military actions is something voters have had ample opportunities to consider.

What should Congress have done instead? Ocasio-Cortez responded to CNN's Jake Tapper on Twitter:

"I think that our decision to enter unlimited engagement in Afghanistan, particularly through the AUMF + Congress' abdication of power + decision-making w/ passage of the AUMF, was a mistake."

I think that our decision to enter unlimited engagement in Afghanistan, particularly through the AUMF + Congress' abdication of power + decision-making w/ passage of the AUMF, was a mistake.



Other options: targeting the network itself, limited engagement, non-intervention. — Alexandria Ocasio-Cortez (@AOC) March 5, 2019

Other options she offered: targeting the network itself, limited engagement, nonintervention.

The idea that after the 9/11 attacks, the US would have embarked upon a diplomatic or nonintervention strategy that didn't involve military force certainly ignores the spirit of that moment. It was, after all, the one time NATO forces have ever rallied to protect an attacked member.

Even Lee wasn't exactly saying the war was wrong when she bravely went to the House floor before her lone vote.

"Our country is in a state of mourning. Some of us must say let's step back for a moment," she said. "Let's just pause, just for a minute and think through the implications of our actions today so that this does not spiral out of control."

Lee argued at the time -- prophetically, it turned out -- that the war vote was open-ended and could lead to unlimited military engagements.

She later quoted a clergyman at the 9/11 memorial when she said, "As we act, let us not become the evil we deplore."

Presidents from both parties have relied on the AUMF to justify military actions not only in Afghanistan, but in other countries, including Syria. While Trump campaigned on withdrawing troops from both theaters, he's found delivering on the promise to be difficult. His first defense secretary, James Mattis, resigned rather than pull troops from Syria . His administration has outright opposed debating a new version of the AUMF. So the AUMF remains in place and the years tick on. It's been used to justify at least 37 actions in at least 15 countries

That creep is certainly up for debate and as the war has dragged on, approval has sagged.

In 2006, as the war in Iraq was going very badly, 69% said the use of military force in Afghanistan was the "right decision," according to a Pew poll. Just 45% said using military force in Afghanistan was the "right decision" in September of 2018.

Lee has consistently tried to repeal the AUMF, a task that started as very lonely but for which she now has growing company, in Congress and the public at large. With help from some Republicans, Lee was nearly able to force a debate on replacing the AUMF in 2017, but Republican House leaders quashed it. It's likely House Speaker Nancy Pelosi will face a similar bipartisan effort now. Pelosi supports an update to the AUMF, but not simply ending it.

Pelosi, who voted against an earlier Lee effort to repeal the AUMF when Obama was still President, has said she wants to have a debate on the issue, particularly as it relates to Syria.

But even among many of those who want to repeal the AUMF, there is hesitance in Congress to say the initial action was wrong. One of the most fervent anti-war senators is Paul, with his libertarian bent and his opposition to nation-building. Paul has announced a bipartisan bill to end the Afghanistan War and force a debate over the AUMF.

Paul and Udall would pay a onetime bonus of $2,500 to every US service member who served in the global war on terror -- more than 3 million of them -- declare victory in Afghanistan since al Qaeda, they say, is no longer capable of attacking the US, and repeal the AUMF.

But even after all these years, Paul says he does not think fighting in Afghanistan, specifically, was the wrong thing to do.

This week, I am introducing legislation to end a war that should have ended long ago, the war in Afghanistan. The United States has been fighting the War on Terror since October of 2001 and it has cost 6 trillion dollars. pic.twitter.com/UBxeq0NsQe — Senator Rand Paul (@RandPaul) March 5, 2019

"I supported going to war in Afghanistan in 2001, attacking those who harbored the 9/11 terrorists or helped to organize the attack on 9/11 and going after al Qaeda," Paul said in a video announcing his new legislation Tuesday. "But we are many, many years past that mission. We have turned to nation-building at a cost of over $50 billion a year spent in Afghanistan. It's important to know when to declare victory and leave a war. I think that time is long past."

Support for the initial decision to strike in Afghanistan has not been at the top of the American political conversation even among Democrats, although support for the war has waned and the AUMF has been stretched far beyond its initial intent.

When Obama was elected, it was by juxtaposing the "bad war" in Iraq with what he implied was the "good war" in Afghanistan . He was going to end the bad war and fix the good war. US troops, all these years later, are still in both places. Trump has tried to argue he opposed the Iraq War, but he never said that about Afghanistan.

Obama, under pressure, suggested a new AUMF to fight ISIS, but Congress did not take action. More recently, a bipartisan group of senators led by Democrat Tim Kaine of Virginia and Republican Bob Corker of Tennessee (since retired) wanted to debate a new AUMF in 2018 and give the President more clearly delineated authority, but the debate never took place . An earlier effort by Paul to end the AUMF in the Senate failed.

Those issues will be up for debate again in 2020. Democratic Rep. Tulsi Gabbard of Hawaii, an Iraq War veteran, has built her campaign around opposition to international entanglements.

Sen. Kirsten Gillibrand, a New York Democrat who is running for President, said recently on MSNBC that there should be a new AUMF.

"I think we should be drawing down our troops, not only in Afghanistan but the remainder in Iraq and Syria, and then give Congress the opportunity that if they believe we should be in combat missions in any of these countries that we actually file a new authorization for the use of military force," she said.

The underlying issue there, though, is whether presidents should come to Congress to authorize new strikes rather than relying on a vote made, nearly unanimously, almost a generation ago, to strike back after an attack. Not whether that vote itself was right or wrong.

If that Pew poll and Ocasio-Cortez's tweet suggest the public or the left regret that initial action, it would require a full and very painful re-examination of 18 years of American foreign policy.