It was only a matter of time before the bombing campaign that NATO nations—including the United States—have waged against Libya would go horribly awry. And so it has. NATO commanders are now acknowledging that their forces bombed residential neighborhoods in Tripoli, killing and injuring civilians over the weekend—just as they previously admitted that misdirected air strikes killed rebels they were supposed to be aiding.

War is a messy business that is frequently defined by “collateral damage.” Civilians get killed. “Friendly fire” takes down allies. That’s reality. And in a necessary war, Americans of many partisanships and ideologies can accept that reality and the need to continue the conflict.

But the Libya fight is not necessary; at least not for the United States. And Americans know that, The latest CBS News poll finds that “six in 10 Americans do not think that the United States should be involved in the conflict within that country. Just 30% of Americans think the United States is doing the right thing by taking part in the current military conflict in Libya now. A majority of Republicans, Democrats, and independents alike think the U.S. should not be involved in Libya.”

President Obama, who steered the United States into the Libya conflict without proper authorization from Congress, has stubbornly refused to reconsider his wrongheaded approach to the conflict. Now we learn, from a New York Times report, that Pentagon’s general counsel, Jeh C. Johnson, and Caroline D. Krass, the acting director of the Justice Department’s Office of Legal Counsel, both advised President Obama that our nation’s involvement in the war in Libya constitutes “hostilities” as defined by the War Powers Act.

Translation: Even the Pentagon and the Justice Department say this was is in conflict with the laws and the Constitution of the United States.

President Obama is wrong.

And it is the job of Congress to address that wrong.

The opportunity could come this week.

House Speaker John Boehner, R-Ohio, plans to offer the House a pair of choices: vote to authorize the US combat mission or vote to bring it to an end.

The first resolution—parallel to a proposal advanced by Senators John Kerry, D-Massachusetts, and John McCain, R-Arizona, that authorizes a limited US military mission of one year in duration. This resolution prohibits the use of ground troops except to defend endangered Americans.

The second resolution demands that, in keeping with the War Powers Act, US forces be removed from Libya “except for forces engaged in non-hostile actions such as search & rescue, aerial re-fueling, operational planning, intelligence/surveillance/reconnaissance, and non-combat missions.”

Even that is too much.

No war should be launched without a Congressional declaration, of the sort sought and obtained by President Franklin Roosevelt before the launch of World War II, and President Woodrow Wilson before World War I.

Boehner covered for Obama on the issue two weeks ago by averting a move—led by Ohio Democrat Dennis Kucinich but supported by many leading Republicans—to demand the rapid withdrawal of US forces from the NATO mission. But, now, the pressure is on both Obama and Boehner.

Ten members of the House—Kucinich, Walter Jones (R-NC), Howard Coble (R-NC), John Duncan (R-TN), Roscoe Bartlett (R-MD), John Conyers (D-MI) Ron Paul (R-TX), Michael Capuano (D-MA), Tim Johnson (R-IL) and Dan Burton (R-IN)—have filed a suit in federal court against President Barack Obama to challenge the commitment of the United States to war in Libya absent the required constitutional legal authority.

Kucinich is not just fighting in the courts. He is again offering an amendment to cut off funds for the continuation of the war.

“This Administration brought our nation to war without Congressional approval or the support of the American people. When Congress demanded an explanation, the administration tried to argue that bombing operations and support of other countries’ military operations in Libya, which cost almost $9.5 million per day, do not constitute war. In a direct challenge to Congress, the Administration is continuing the war despite its inability to provide a constitutional or legal justification for bypassing Congress. Congress must use its constitutional authority of the power of the purse to end this war.

“My amendment will provide the first test whether this Congress will defend its own authority under Article 1, Section 8 of the Constitution,” says Kucinich. “The war in Libya lacks Constitutional authority and it lacks the support of the American people.… I am proposing this amendment to bring our engagement to a swift end.”

Kucinich and his allies on the left and right are the real leaders in the fight to hold the president to account. Boehner, the president’s golf partner, is feeling the heat—and his proposed resolutions could be vehicles for ending not just an war but an assault on the constitution.

But don’t waste too much time trying to keep track of Boehner’s machinations, which may or may not prove to be consequential.

Watch what Kucinich and his allies do. The Ohioan and the Democrats and Republicans who have sided with him as unflinching defenders of the Constitution and the strict application of the War Powers Act are the steadiest fighters on this issue. Where they take their stand—particularly on Boehner’s second resolution—will be the right and proper checks-and-balances stance. They are the true defenders of the system of checks and balances.