President Obama notched another victory in the war on terror Monday, when a CIA drone strike killed al Qaeda's second-in-command in Pakistan. No one should mourn the death of Abu Yahya al-Libi, a charismatic terrorist who had risen to assume operational leadership after Osama bin Laden's death last year at the hands of Navy SEALs.

Al-Libi's death, however, may represent tactical success in the drone war at the expense of broader strategy. Recent stories in major newspapers portray a White House war room where Mr. Obama studies the files of potential targets, compiles a "kill list," and makes the final decision on strikes—at last count, 269 in Pakistan, 38 in Yemen.

"He is determined that he will make these decisions about how far and wide these operations will go," Thomas Donilon, the White House national security adviser, told the New York Times. "He's determined to keep the tether pretty short."

The administration has made little secret of its near-total reliance on drone operations to fight the war on terror. The ironies abound. "The administration has made little secret of its near-total reliance on drone operations to fight the war on terror. The ironies abound." -- John Yoo Candidate Obama campaigned on narrowing presidential wartime power, closing Guantanamo Bay, trying terrorists in civilian courts, ending enhanced interrogation, and moving away from a wartime approach to terrorism toward a criminal-justice approach. Mr. Obama has avoided these vexing detention issues simply by depriving terrorists of all of their rights—by killing them.

Some information about these strikes comes from the disclosure of national secrets that appear designed to help the president's re-election. Recent leaks have blown the cover of the Pakistani doctor who sought to confirm bin Laden's presence in Abbottabad; revealed a British asset who penetrated al Qaeda and stopped another bombing of a U.S.-bound airliner; and assigned credit to the administration for the Stuxnet computer virus that damaged Iran's nuclear program (even identifying the government lab that designed it).

American intelligence will have a steep hill to climb when it asks for the future cooperation of agent-assets and foreign governments. Notably silent are the Democrats and media figures who demanded the scalp of a Bush White House aide, Scooter Libby, for leaks by another government official of the cover of a CIA operative who had left the field years earlier.

Yet the greater threat to security comes from Mr. Obama's micromanagement of the drone campaign. Poring over the files of kill-list nominees recalls Lyndon Johnson's role in tightly controlling bombing strikes during the Vietnam War. During Operation Rolling Thunder, Johnson held Tuesday lunches when he and his advisers picked targets to avoid attacks that might provoke Soviet or Chinese intervention.

This misuse of presidential time produced a myopic focus on tactics. Photos of LBJ hunched over maps said it all: Staring at individual targets prevented him from seeing the broader strategic picture in Vietnam and Southeast Asia. Worse yet, it encouraged the military to set aside its judgment in favor of the president's political preferences.

In Vietnam, LBJ and his advisers placed off limits vital targets in Hanoi, Haiphong harbor and the North's supply chains, preventing the U.S. military from striking the enemy's war-making capacity and isolating the North from its allies. Today the Obama administration commits mistakes of similar dimension by rushing for the exits in Iraq, hastily drawing down in Afghanistan, and failing to pressure Pakistan to control its western regions, where al Qaeda and the Taliban operate with little restraint. America's high-tempo drone campaign cannot succeed for long without the ground support of local bases and intelligence assets.

To stop an enemy without territory, population or regular armed forces, the U.S. must have access to timely, actionable intelligence gleaned from captured terrorists. The interrogation of terrorist leaders not only led the CIA to bin Laden's doorstep. It helped produce the success of the last decade: not a single follow-up al Qaeda attack in the U.S. Exclusive reliance on drones and a no-capture policy spend down the investments in intelligence that made this hiatus possible, without replenishing the interrogation-gained information needed to predict future threats.

According to press reports, aides claim the president is a student of St. Augustine and St. Thomas Aquinas who brings their views to targeting choices. This is scarcely believable.

But even taking the claim at face value, just-war theory should broaden, rather than limit, the use of force against terrorists. The work of the Catholic theologians drew upon traditions stretching back to the ancient world that would have considered terrorists to be hostis humani generis, the enemy of all mankind, who merited virtually no protections under the laws of war.

Some church thinkers approved of wars for conversion (i.e., the Crusades), reprisal, conquest and punishment. While Mr. Obama surely does not seek a return to these earlier forms of conflict, a return to first principles such as hostis humani generis may prove a better guide for a nation at war than a president's day-to-day instincts.

Mr. Yoo, a professor at the University of California at Berkeley School of Law who served in the Bush Justice Department, is the author of "Taming Globalization" (Oxford University Press, 2012)