It is not a lack of sympathy with the historic and current circumstance of Iraq’s religious minorities—or of other persecuted peoples in that traumatized country—that leads some of the most humane and responsible members of Congress to say that President Obama must seek approval from the House and Senate before committing the United States military to a new Iraq mission.

Nor is it isolationism or pacifism that motivates most dissent.

Rather, it is a healthy respect for the complex geopolitics of the region combined with a regard for the wisdom of the system of checks and balances and the principles of advice and consent outlined in the US Constitution.

Consider the case of Barbara Lee.

Few members of the House of Representatives have a so long and distinguished a record of commitment to respecting and protecting the interests of vulnerable populations in distant lands than Lee, a California Democrat who has been deeply engaged in international human rights advocacy since her days as an aide to former Congressman Ron Dellums, D-California.

Since her election to Congress in 1998, Lee has been the essential author or co-author of major pieces of legislation dealing with international HIV/AIDS issues, including the measure that created the Global Fund to Fight HIV/AIDS, TB and Malaria. She organized bipartisan coalitions to respond to genocide in Darfur.

She was a leader the effort to establish the position of special adviser for orphans and vulnerable children. She has served as a US representative to the United Nations. And she has argued, well and wisely, that the hard work of diplomacy, the provision of humanitarian aid, the steady support of international institutions and the recognition of distinct regional issues is invariably more likely to help the world’s most vulnerable peoples than war-making.

Of course Barbara Lee supports immediate and intensive efforts to provide vital aid to the Yazidi people, a religious minority facing harrowing threats from the militant forces of the Islamic State of Iraq and Syria. Of course, she wants to aid and protect religious, cultural and ethnic minorities.

That is why she was one of the first members of the House to express support for “humanitarian efforts to prevent genocide in Iraq.”

Lee praises the president for announcing that “there’s no American military solution to the larger crisis in Iraq.”

But she still expresses legitimate concern about “US mission creep in Iraq and escalation into a larger conflict, which I oppose.”

Within hours of President Obama’s announcement that, in addition to humanitarian efforts, he was authorizing military airstrikes on ISIS forces, Lee called for the president “to seek congressional authorization before any combat operations.”

“For too long, Congress has abdicated its Constitutional role in matters of war and peace,” she explained. “The President should come to Congress for authorization of any further military action in Iraq.”

Lee is not alone in w orrying about the threat of US mission creep in Iraq .

Congressman Jim McGovern, the Massachusetts Democrat who has been an outspoken advocate for hunger relief and related humanitarian initiatives, warned with regard to the airstrikes ordered last week by the president, “These strikes do involve the United States directly in hostilities, regardless of how limited they are and regardless of whether there’s a humanitarian purpose involved. “

In July, the House voted overwhelmingly for a resolution written by McGovern, Lee and Congressman Walter Jones, R-North Carolina, which explicitly signaled opposition to any prolonged US military intervention in Iraq without congressional approval. “We made it very clear that we believe Congress has a significant constitutional role to play,” says McGovern, who explains, “When we bomb ISIS, which is a horrible group, we have to realize that we are heading down the path of choosing sides in an ancient religious and sectarian war inside Iraq. While choosing sides may be something Congress decides that it wants to support, it goes beyond the humanitarian mission of providing relief to civilians stranded on a mountain in imminent danger of dying of hunger and thirst. It goes beyond protecting our military and diplomatic personnel. I am concerned that we are already seeing these different missions blur into one in the press and in Congress. That is deeply troubling.”

Congressman John Garamendi, a California Democrat who has remained deeply involved with conflict resolution in the African region where he served as a Peace Corps volunteer, was quick to voice support for the “ongoing humanitarian mission of airdropping food and water” into Iraq. But he added, “I am seriously concerned that these targeted strikes may become a slippery slope.”

Garamendi says, “Congress needs greater clarity on the objectives of this expanding action.”

That clarity will benefit not just Congress but President Obama.

Even close allies of the president, such as Illinois Senator Dick Durbin, the number-two Democrat in the Senate, insist that escalation “is not in the cards.”

“We cannot send the troops, we must not send the troops,” Durbin argued on NBC’s Meet the Press. “Escalating it is not in the cards. Neither the American people nor Congress are in the business of wanting to escalate this conflict beyond where it is today. I think the President’s made it clear this is a limited strike. He has, I believe, most Congressional support for that at this moment. To go beyond is really going to be a challenge.”

Arizona Senator John McCain and his neoconservative allies take a different view, as do some liberal interventionists. But the necessity of congressional debate is about more than partisanship and ideology. All sides should recognize not just the requirement of congressional consent but the value of the process.

There is a mistaken notion that the system of checks and balances threatens the authority of the presidency. In fact, it can, and often does, provide necessary definition for a commander in chief. When a president seeks the advice and consent of Congress for military intervention, the process itself conveys authority—along with a broad understanding of the mission that is being proposed.

This is as the founders of the American experiment intended, and that intent remains entirely appropriate. If a president proposes a fool’s mission, Congress should be able to prevent him from embarking upon it. If a president proposes a necessary mission, Congress can and in all likelihood will give approval—not always as quickly as the commander in chief would prefer, but on a timeline (and wi th parameters) that will balance executive urgency with legislative caution.

It is not a lack of conscience, or humanity, that inspires the demand that every president—be he a Democrat or she a Republican, be he a conservative or she a liberal—seek the approval of Congress before intervening militarily in a distant land. It a basic premise of the American experiment, as outlined in our Constitution and in our common sense of who we are and how we might best respond to a dangerous and difficult world.