An Iran-backed Hezbollah commander who killed American soldiers in cold blood has been in U.S. custody for four years. Most Americans would see this as a good thing. For the Obama administration, it is a vexing dilemma. This highlights, yet again, why the country can’t afford a second Obama administration.

Ali Mussa Daqduq has been a Hezbollah operative for almost 30 years. He is the hardcore. When he joined back in 1983, the “Party of God” (hizb Allah) was just getting its start as Iran’s forward militia in Lebanon, announcing its allegiance to Ayatollah Ruhollah Khomeini and killing hundreds of Americans in bombings, abductions, and hijackings that targeted U.S. military personnel, intelligence agents, and civilians. Daqduq quickly climbed the ranks, becoming a top terrorist trainer in an organization so adept that al-Qaeda began taking its instruction in the early 1990s. He rose to command Hezbollah’s most lethal cells and even ran the security detail for its leader, “secretary general” Hassan al-Nasrallah.

It was only natural, then, that Iran turned to Daqduq in 2005 when the mullahs decided to reprise in Iraq the strategy that had worked so well in Lebanon. He was tasked with building an Iraqi version of Hezbollah: a jihadist network that would first use terrorist attacks to sap America’s will to remain in the region and then be poised to seize de facto control of the country — to run Iraq as an Iranian satellite.

It worked like a charm. As Bill Roggio recounts at The Long War Journal, Daqduq partnered with Iran’s deadly special-operations unit, the Quds Force, to set up an intricate web of Shiite terror cells. Battalions of 20 to 60 recruits were brought to Iranian bases for schooling in close combat tactics, kidnapping, and intelligence collection, while also learning to use explosively formed penetrators, mortars, rockets, and sniper rifles. When their training was complete, they were loosed on Iraq. Fueled by Iranian supplies, they targeted and killed American and allied forces. Most notoriously, they carried out the January 2007 Karbala massacre, in which five American soldiers were killed, four of them as captives, handcuffed and shot before U.S. rescue teams could close in.

Daqduq was captured by American forces two months later. He has been in the custody of our military in Iraq ever since. He is not a defendant. He is not a capo in some Iranian Cosa Nostra family. He is a terrorist enemy of the United States, who has committed atrocities against American soldiers during a war authorized by Congress. Compared with him, most al-Qaeda jihadists are pikers. Hezbollah is as bad as it gets, and Daqduq is as bad as Hezbollah gets.

If one accepts that the object of war is to defeat the enemy, there is no doubt about what must happen here. Under the laws of war, Daqduq is an enemy combatant: He may be detained until the conclusion of hostilities, subjected to trial by military commission, and put to death — or, at the very least, imprisoned for the rest of his life.

These laws of war are codified in American statutes. Candidate Obama may have pined for a return to the law-enforcement approach to counterterrorism (i.e., treating alien enemies as mere defendants entitled U.S. constitutional protections and civilian trials), but President Obama has grudgingly accepted — at least on paper — the need to maintain combatant detention and trial by military commission. In 2009, he signed a cosmetic revamping of the Military Commissions Act (MCA). Under it, unlawful enemy combatants — who are now called “unprivileged enemy belligerents,” lest the use of Bush terminology betray the adoption of Bush methods — may be detained by our armed forces and tried by commission if they have “engaged in” or “purposefully and materially supported” “hostilities against the United States.” The definition fits Duqdaq to a tee.

In saner times, this one would be easy. Daqduq should be transferred to Guantanamo Bay. . .

The plan was to transfer Daqduq to the Iraqi regime as early as yesterday — without fanfare, the administration hoped, the debt ceiling crisis having saturated news coverage on a mid-summer Friday. But the Associated Press got wind of the transfer, and its brief report provoked outrage. Senate Republicans, joined by independent Joe Lieberman, fired off a letter to secretary of defense Leon Panetta, ballistic at the notion that the United States would surrender “the highest ranking Hezbollah operative currently in our custody.” Inevitably, the senators observed, Daqduq would return to the jihad “to harm and kill more American servicemen and women” when Iraq releases him, as these new “allies” of ours have done with other terrorists.

The unexpected blowback caused the administration to retreat on its release plan . . . at least for the moment.