Congressman Peter Welch has done his due diligence. He has studied the circumstances on the ground in Syria and surrounding countries. He has traveled to the region as part of a congressional oversight trip. He has visited centers for refugees on the Syrian-Turkey border. The Vermont Democrat, who serves on the Subcommittee on National Security, Homeland Defense, and Foreign Operations of the House Committee on Oversight and Government Reform, has gone out of his way to engage in debates, discussions, and inquiries regarding US policy in the region.

So the congressman’s words should carry particular weight when he discusses last week’s decision by President Obama to put US troops on the ground in Syria. After the president—who once declared, unequivocally, that “we’re not considering any boots-on-the-ground approach” in Syria—ordered several dozen Special Operations troops into Syria for what The New York Times describes as “the first open-ended mission by United States ground forces in that country,” Welch said: “Make no mistake about it, this is a war.”

It is not, however, a clearly declared or authorized war.

As Welch observes: “The legal framework justifying this war is loosely tied to the fumes of a Congressional authorization approved in response to the 9/11 attack on America over 14 years ago.”

That’s an absurd construct, argues Welch.

“A civil war in Syria did not exist 14 years ago. ISIS did not exist 14 years ago. Neither the United States nor Russia were conducting military operations in Syria 14 years ago,” notes the congressman, who says it is time for Congress to focus on the question of whether the United States should be engaged in a new war in the Middle East.

“The biggest question raised by [deployment] announcement is, ‘When will Congress finally accept its responsibility?’” says Welch, who adds that “The Constitution is clear that only Congress can authorize war.”

Welch is not alone in expressing concern about a military intervention that is expanding in scope and character—in Syria and in Iraq—without adequate approval or oversight from Congress.

“I am deeply concerned by escalating mission creep in Syria, especially since Congress has yet to debate the costs and consequences of this military operation,” says Congresswoman Barbara Lee, D-California, a longtime supporter of the president who served as a Representative of the United States to the 68th Session of the General Assembly of the United Nations. “The Constitution is clear: the power to declare war rests with Congress. We serve as the voice of the American people—our actions in Congress should reflect that sacred responsibility.”

Senator Brian Schatz, D-Hawaii, decries the decision to dispatch troops to Syria as “a strategic mistake.”

“The Administration’s announcement that it will deploy Special Operations Forces into Syria to combat ISIL marks a major shift in US policy—a shift that is occurring without congressional debate—is unlikely to succeed in achieving our objective of defeating ISIL and instead threatens to embroil the United States in Syria’s civil war and could bring us into direct confrontation with the Russian Federation military and Syrian government forces,” says Schatz. “In the 16-months since the United States began its participation in the regional fight against ISIL, our military involvement has escalated without a clear sense of how our escalating involvement will achieve our strategic objectives. With ISIL’s control of northern Syria, we cannot reasonably expect that the deployment of Special Operations Forces would be limited in scope or duration.”

This is a big issue, yet it has received scant attention from media and political elites. As such, many Americans are unaware of the seriousness, and the potential consequences, of the Obama administration’s policy shift.

There should be no question that a congressional debate is required—and needed. Americans should be brought into this discussion, and the way to do that is by raising the issue in Congress. The House and Senate should reject the flimsy excuse of a 14-year-old AUMF and vote on whether to authorize the growing intervention that the administration is now implementing across Iraq and Syria.

“Congress must act immediately to repeal the 2001 and 2002 authorizations for military force (AUMFs), which continue to be used as blank checks for endless war,” says Congresswoman Lee. “It is past time for our elected officials to recognize that there is no military solution to the problems in the region. Only a comprehensive, regionally-led strategy that addresses the underlying political, economic, humanitarian and diplomatic challenges can ultimately degrade and dismantle ISIL.”

It is not certain that Congress would say “no” to intervention of the sort that Obama proposes—even if there are contingents on both the Democratic and Republican parties that believe, as Senator Rand Paul, R-Kentucky, does, that “the fighting on the ground needs to be done by the people who live there.”

There are genuine divisions on this issue. “The senator believes that the crisis in Syria will be solved diplomatically, not militarily,” says the campaign of Democratic president campaign of Senator Bernie Sanders, while the campaign of Hillary Clinton says the former secretary of state “sees merit in the targeted use of special operations personnel to support our partners in the fight against ISIS, including in Syria.”

This debate can, and should, be had on the campaign trail.

But it must be had in Congress.