In the coming months, we’ll hear that confrontation with Iran is preferable to diplomacy. Most people making this argument will say that they want to avoid war—the party line is that piling on the sanctions will help negotiations by forcing Tehran to the bargaining table—but some of them are already pressing for an authorization of military force.

Authorize the use of force first, negotiate later? That was Sen. Lindsey Graham’s position before there was an interim nuclear deal in place.

A few of these arguments will resonate on the right. The Iranian regime is certainly loathsome. The Obama administration is untrustworthy. But there is some obvious context to consider that doesn’t require any optimism about Iranian intentions or John Kerry’s competence.

Let’s start with Afghanistan, the longest-running war the United States has engaged in. According to a CNN poll, public support for that intervention has collapsed from 52 percent in December 2008 to just 17 percent at the end of 2013. Fully 82 percent of the American people now say they oppose the war.

“Opposition to the Iraq war never got higher than 69% in CNN polling while U.S. troops were in that country, and while the Vietnam War was in progress, no more than six in 10 ever told Gallup’s interviewers that war was a mistake,” remarked CNN polling Keating Holland. When President Obama announced his Afghanistan surge in December 2009, a Pew poll found that only 32 percent approved.

In Iraq, there are now multiple reports that Fallujah has fallen under al-Qaeda control as militants continue a nationwide reign of terror. At the height of the Iraq War, U.S. forces retook the city at great cost. “The handwriting is on the wall,” concluded one analysis. “The Battle of Fallujah was not a defeat—but we cannot afford many more victories like it.”

There are those who blame these developments on the departure of U.S. combat troops. Perhaps this could have been avoided if we really did remain in Iraq for 100 years. But another way of looking at it is that after 4,500 Americans dead, 35,000 wounded, and $1.7 trillion spent, the type of Islamic militants who attacked us on 9/11 now have a greater foothold in Iraq than before we invaded.

It was the Iraqi government that the United States put in place that wanted American troops to leave, despite the Obama administration’s efforts—however half-hearted—to negotiate a status of forces agreement that would have left them there longer. Were we to undertake regime change again to preserve the occupation? The mission had long morphed from keeping Iraqis from killing Americans, if that was ever necessary, into keeping Iraqis from killing one another.

What of our so-called victory in Libya, where we avoided “boots on the ground?” Muammar Gaddafi is gone. But the country has descended into chaos. Islamist militias are grabbing U.S. arms shipments. The consequences have spread to Tunisia, where jihadists are moving weapons across the border.

Some blame U.S. inattention rather than intervention for the anarchy consuming Libya. But did the “kinetic military action” help? And would American interests have been better served by exposing more of our citizens to Benghazi-like situations?

What do we have to show for these large-scale military efforts? A war that began in retaliation for the 9/11 terrorist attacks, one that this writer agrees was necessary at the time (if not a dozen years later), is now less popular than Vietnam. Over 40 years, Afghanistan and Iraq may cost $6 trillion.

These disasters of America’s post-9/11 foreign policy kept the country out of war in Syria, where rebel forces are as dubious as the regime. This sorry track record is also worth surveying as we confront Iran’s nuclear program.

Is not diplomacy, however imperfect and fraught with risk, preferable to military action that could easily metastasize into another no-win war? Have we not spent enough blood and treasure on preventive war with little obvious benefit?

As the Iran debate escalates, we’ll hear many analogies to Munich in 1938. But Afghanistan, Iraq, and Libya in the past decade are at least as worthy of consideration.

W. James Antle III is editor of the Daily Caller News Foundation and author of Devouring Freedom: Can Big Government Ever Be Stopped?