WASHINGTON — Sixteen years ago, Rep. Barbara Lee was the sole member of Congress to vote against authorizing the U.S. invasion of Afghanistan. She warned at the time that granting President George W. Bush open-ended approval to use military force would lead to “war without end.”

In seeming fulfillment of the Oakland Democrat’s prophecy, President Trump announced Monday night that the United States must continue fighting in Afghanistan to avoid the “predictable and unacceptable” results of a rapid withdrawal from the country. Congressional officials said the administration has told them it will add about 4,000 troops to the Afghanistan force, although Trump did not specify a number in his speech.

Trump’s announcement came during his first prime-time television address to the nation outlining his Afghanistan strategy.

Throughout the presidencies of Bush and Barack Obama, Lee waged a lonely crusade to repeal the war resolution initially aimed at al Qaeda’s Sept. 11, 2001, attacks on New York and Washington. Last month, she won a stunning victory when a bipartisan House committee voted to repeal the authorization in an amendment to the 2018 defense spending bill.

But her win was short-lived. House Republican leaders stripped the amendment from the bill without a vote in a late-night maneuver that blocked Lee from leading a larger House debate on the president’s use of military force without further approval by Congress.

The 2001 authorization was passed by Congress three days after the 9/11 attacks. “It was hastily written; it was overly broad; it was 60 words,” Lee said. Citing the Congressional Research Service, a nonpartisan arm of Congress, Lee said presidents have used the authorization at least 37 times since the initial Afghanistan invasion in October 2001.

Republicans “know we need to take this off the books, and we need a full debate and to make some decisions about whether or not we are going to continue in these wars or not,” Lee said. “That’s our constitutional responsibility.”

Trump’s announcement comes after months of White House deliberations and internal dissension about a new strategy for the war in Afghanistan, the longest in American history. It arrives on the heels of the departure of Trump’s chief political strategist, Stephen Bannon, who had argued against escalating the conflict. Defense Secretary James Mattis and National Security Adviser H.R. McMaster, both generals, favor trying a larger U.S. military presence to stabilize the country.

Previously, Trump was a longtime critic of the Afghanistan war, flouting GOP orthodoxy during the presidential campaign by arguing against overseas military interventions. In 2013, before he ran for president, he had gone so far as to argue for a withdrawal from Afghanistan.

Two previous presidents increased troop levels in Afghanistan in an effort to thwart terrorist groups from operating there. Bush, a Republican, had anticipated a quick exit after the 2001 invasion, but was never able to stabilize the country despite several troop “surges.” Obama, a Democrat, brought troop levels to a peak of 100,000 in 2010, and later sharply reduced the U.S. military presence and scheduled an exit for 2016 that never occurred. About 8,400 U.S. troops are in the country.

Lee’s amendment last month had passed the Appropriations Committee on a voice vote, with favorable comments from several Republicans, including Oklahoma Rep. Tom Cole, chairman of the committee’s defense panel. But Republican leaders removed the amendment without a vote before the bill reached the floor.

“In the dark of night, it just disappeared” when the defense bill was posted online, Lee said of her amendment. “I think it was a 326-page bill. The only part of that bill that was taken out was my amendment. So that was, if you ask me, underhanded; it was undemocratic; it was wrong.”

Lee said she will try again, as she has over the past decade, to repeal the war authorization, arguing that doing so is more necessary than ever with what she called Trump’s “saber-rattling” with nuclear-armed North Korea.

“I’m going to keep coming back until we get this done, and it will get done,” Lee said. “It took a good while just to get this far, but we’re going to keep at it. We’re persisting on this, because the American people deserve their representatives to stop missing in action and to do our job.”

Lee said it is especially important to have a “congressional debate and determination if the president should engage in a first strike as it relates to nuclear weapons.” Under the current authorization, she said, “we could see ourselves embroiled in another war — God forbid, a nuclear war — without congressional authorization, because they’re continuing to use this blank check to engage in wars all around the world.”

She said House Speaker Paul Ryan, R-Wis., defended his removal of her war authorization amendment by arguing that it would leave troops exposed to danger. Lee said that is not the case, because Congress would have eight months to decide on a new military authorization.

The administration, Lee noted, has proposed severe cuts to domestic spending to pay for a bigger military. Escalating the Afghanistan conflict, she said, will come at the expense of “schools and infrastructure and jobs and health care — all the nation-building resources that we need here, here in my own district.

“Yet they’re cutting these programs to fund these wars, and that’s unfair to taxpayers; it’s unfair to constituents; it’s unfair to the country,” she said.

A settlement in Afghanistan, Lee said, should be led by countries in the region.

“There’s no way the U.S. is going to win a civil war in Afghanistan,” she said. “I’m confident and certain that adding more troops will just dig us deeper into a hole and deeper into a civil war that we should not be in. I think it’s very dangerous.”

The Washington Post contributed to this report.

Carolyn Lochhead is The San Francisco Chronicle’s Washington correspondent. Email: clochhead@sfchronicle.com Twitter: @carolynlochhead