Since arriving in the Senate in 2011, Rand Paul has been probing here and there for issues of populist resonance. Audit the secretive, sinister Federal Reserve. Rein in those TSA screeners patting down little girls. In each instance, Paul (R-Ky.) has evoked the fear of oppressive government without tipping over into the paranoia of his father’s most dedicated supporters. It has been a diluted, domesticated, decaffeinated version of the ideology that motivated Ron Paul’s presidential races.

On drones, Rand Paul finally hit pay dirt. Thanks to his filibuster, Americans can now feel safe that if they are “typing e-mails in a cafe,” they will not be “summarily executed” by a Hellfire missile. This has admittedly not been a large problem since 9/11. Paul is careful to point out that he is concerned about the possible abuses of some future, Hitler-like president. (Though one imagines the advent of a Hitler-like president would present problems other than drone policy.)

Seeking an unobjectionable assurance, Paul was aided by a bungling Obama administration, at first incapable of effectively articulating its own policy. The Justice Department memo on drone strikes leaked last month said that a target must present an imminent threat of violence; capture must not be feasible; and the operation must comply with the rules of war. Offing a noncombatant at a Starbucks in Pittsburgh is not an option. But it took some time for the attorney general to say this plainly.

In the interval, Paul gathered the sudden, unexpected, Internet-driven momentum of a varied coalition. There were, of course, paleoconservatives who believe a tyrannical dystopia has already arrived. Paul feeds their fears on talk radio: “I am worried about them doing surveillance without warrants, flying over my farm, watching where I hunt, things like that.” It is bad enough to be killed in a cafe. But warrantless hunting surveillance? Will they stop at nothing?

But this group was joined by partisan Republicans who enjoyed watching the Obama administration squirm and yield. And by some, on the left and right, who believe that the drone program has inadequate oversight, or that U.S. security policy is overly reliant on targeted killings, or that the whole enterprise is ethically suspect.

It was Paul’s political genius to pick a ripe populist issue and drive home one narrow, uncontestable point. But in the course of a 13-hour filibuster, it becomes impossible to hide your deeper motivations. Paul employs the prospect of drone murders in an attempt to discredit the “perpetual war” in which “the whole world is a zone of war.” His actual target is the war on terrorism, which he regards as unconstitutional and counterproductive.

When Paul spoke at last summer’s “We Are the Future” rally in Tampa, he praised his father in particular for raising the issue of “blowback.” “Had he not talked about blowback,” said the younger Paul, “I don’t think anyone ever would have.” This, in the Paulite milieu, is the idea that U.S. policies of aggression and empire provoke terrorist attacks. In his own speech at that rally, Ron Paul claimed that if his non-interventionism had been in force, the 3,000 people killed on 9/11 would still “be alive.”

In various settings, Rand Paul has described himself as a foreign policy “realist.” But this is not the ideology of Chuck Hagel or others skeptical of democracy promotion and nation-building. Paul’s “constitutional foreign policy” denies the legal basis for the war on terror, would place severe constraints on the executive in defending the nation and hints at the existence of an oppressive national security state.

These views are not new. They were central to Ron Paul’s presidential runs. But now they have an advocate who is more skilled, picks his fights better and possesses a larger platform. If the younger Paul runs for president in 2016, it will set up a lively debate on foreign policy fundamentals.

On the other side of that debate are two administrations and the majority of members of Congress from both parties who, since 9/11, have found the threat of terrorism both real and unappeasable. In this period, the American government, with congressional authorization, has destroyed terrorist training camps; undermined terrorist communications, fundraising and planning; targeted terrorist leaders; and disrupted at least 40 plots aimed at U.S. targets.

Far from perpetrating imaginary terrors on Americans, the government has protected them from real ones. Which is the reason that ­Republicans, in the end, cannot ­#StandWithRand.

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Ann Telnaes animation: With his “kill list,” Obama follows in Bush and Cheney’s footsteps. (Ann Telnaes/The Washington Post)