In an interview with The New York Times last month, President Obama confessed that when he decided to help rebels overthrow Libyan dictator Muammar al-Qaddafi in 2011, he "underestimated" the ensuing chaos. "That's a lesson that I now apply every time I ask the question, 'Should we intervene militarily?'" Obama said. "Do we have an answer [for] the day after?"

It would be nice to have a president who looks before he leaps into other countries' civil wars, who learns from his predecessors' foreign policy blunders instead of his own. Rand Paul, who offers a refreshing contrast to the reckless interventionists of both major parties, might be that man.

The Kentucky senator, who is widely expected to seek the 2016 Republican presidential nomination, understands that the U.S. government has neither the mandate nor the ability to solve all the world's problems. He reminds "the let's-intervene-and-consider-the-consequences-later crowd" that there are constitutional and practical limits to U.S. military power and that even the best-intentioned meddling can make a bad situation worse.

In both Iraq and Libya, Paul argues, U.S. intervention deposed nasty dictators but left a power vacuum that even nastier jihadists rushed to fill. He warns that something similar could happen in Syria.

"To interventionists like former Secretary of State Hillary Clinton," Paul wrote in a Wall Street Journal op-ed piece last week, "we would caution that arming the Islamic rebels in Syria created a haven for the Islamic State. We are lucky Mrs. Clinton didn't get her way and the Obama administration did not bring about regime change in Syria. That new regime might well be ISIS."

Responding to Paul's essay, the Democratic National Committee (DNC) claimed he "blames America for all the problems in the world." DNC spokesman Michael Czin called Paul's ideas "reckless" and "isolationist," adding that "if Rand Paul had a foreign policy slogan" it would be "Blame America. Retreat from the World."

As Ezra Klein observed on Vox, "This is the brain-dead patriotism-baiting that Democrats used to loathe. Now they're turning it on Paul."

Presumably the DNC was provoked by Paul's shot at Clinton, the leading contender for the Democratic presidential nomination. But Paul also faulted "hawkish members of my own party" for supporting regime change in Syria, which "would have eliminated the only regional counterweight to the ISIS threat."

At a Paul appearance in Dallas last Friday, I asked him why so many conservatives who are skeptical of the government's ability to reorganize health care, the auto industry, or energy production do not blink at the prospect of reorganizing entire countries. "Sometimes conservatives do seem to have a double standard," he said. "They argue one thing for domestic policy, then they argue the opposite for international policy."

"It's a contradiction," Paul added, "thinking that we can basically build nations overseas, that we can construct a whole nation out of nothing. It just hasn't worked."

Paul argues that such misadventures would be less likely if presidents did what the Constitution requires: seek congressional approval to wage war, except in response to an actual or imminent attack on the United States. He notes that Obama, who as a presidential candidate in 2007 promised to abide by that requirement, cited Qaddafi's attack on rebels in Benghazi as justification for launching air strikes in Libya without congressional authorization.

"Under that sort of theory," Paul said in Dallas, if "any city, anywhere in the world" is "under attack by anyone," the president "could unilaterally go to war." The fact that Paul is tarred as "isolationist" for rejecting this breathtakingly broad view of the president's powers and America's role in the world tells you something about the narrowness of what passes for a foreign policy debate in this country.

If the next presidential contest pits "a very hawkish Hillary Clinton" against "a Republican who is more judicious and more prudent," Paul said, "you could have a transformative election." Or at least an interesting one.