When it comes to Ahmed Abu Khattala, the Obama administration is literally and figuratively at sea.

After capturing the alleged mastermind behind the 2012 attack on a U.S. diplomatic post in Benghazi, U.S. authorities are treating him as an enemy combatant who should be interrogated to prevent another attack.

At the same time, Attorney General Eric Holder plans to press charges against the militia leader in a U.S. court, which would require treating him more like a criminal defendant.

The solution? Investigators put Khattala on a slow boat to the United States.

The Obama administration is using the USS New York as a floating interrogation cell, an area of legal limbo where Khattala is not under either U.S. criminal law or the international law of war for days, possibly weeks.

U.S. authorities could easily have him transported to the states by plane, but because they plan to try him in a civilian court, U.S. law would require they read him his Miranda rights once he arrives, rendering any subsequent interrogations useless.

The decision to keep him in international waters shows just how tricky U.S. criminal law and the law of war have become post-9/11.

A constitutional scholar, President Obama vowed to clean up America's act after his predecessor, President George W. Bush, kept detainees in secret CIA prisons known as “black sites” in countries such as Romania for years without access to courts or lawyers and sent detainees to the Guantanamo Bay prison.

But the president, who famously vowed to close Gitmo, has found that easier to say than to do. Every time Obama decides to interrogate a prisoner at sea, he gets tangled up in legal lanyards.

Over the past few years, U.S. authorities have kept other captured terrorism suspects, such as al-Shabaab operative Ahmed Abdukadir Warsame, a reported 90 days in 2011 before even announcing his detention.

Last year, a suspected al Qaeda operative, Abu Anas al Libi, was interrogated for a week aboard a U.S. warship before being brought to New York for trial. Al Libi is accused of helping plot the 1998 U.S. embassy bombings in Tanzania and Kenya. Intelligence operatives had planned to question him for weeks aboard the Navy ship but health concerns and his refusal of food and water cut it short.

In addressing plans for Khattala, a White House spokeswoman took pride in the fact that the Obama administration has yet to add a detainee to Guantanamo.

“The administration's policy is clear on this issue: we have not added a single person to the GTMO population since President Obama took office, and we have had substantial success delivering swift justice to terrorists through our federal court system,” National Security Council spokeswoman Caitlin Hayden said in a statement.

But for all the controversy surrounding Guantanamo Bay, the island facility is legal under the international law of war, unlike the Navy's floating interrogation facilities. The Geneva Conventions require prisoners of war to be held on land at a fixed address that outside monitors can locate and inspect. If a detainee were held on a ship or airplane heading full speed toward a destination on land, no one would object.

But a ship doesn't have to swiftly make a beeline for a port, leaving Khattala beyond the reach of the law for an unknown length of time.

Democrats have rushed to Obama's defense on his decision to try terrorism suspects in U.S. criminal courts, not military tribunals.

Sen. Dianne Feinstein, D-Calif., who chairs the Senate Intelligence Committee and is a senior member of the Judiciary panel, said Tuesday that she fully supports the Obama administration's “efforts to prosecute [Khattala] in a federal court.”

“The U.S. criminal justice system has successfully convicted over 500 terrorists since 9/11, and I have full confidence in the ability of our federal courts,” she said.

Sen. John McCain, R-Ariz., told the Washington Examiner he hopes Khattala's not enduring some form of torture just because he's in a watery legal limbo.

"I think he can be kept and interrogated without being tortured for an extended period of time," McCain said, "but under the Geneva Conventions, he is not a criminal."

Sen. Lindsey Graham, R-S.C., who wrote the law governing military tribunals for terrorism suspects after 9/11, has supported transferring terrorists from Guantanamo to a military prison inside the U.S.

Still, until Congress approves the creation of a new military prison facility within the U.S. for detainees, he says Khattala and others should be brought to Guantanamo.

“I don't want to hold him forever as an enemy combatant, I don't want to try him at Gitmo — but want I want is a process that allows us to gather intelligence in a more logical, military fashion,” he told the Washington Examiner.