Remember when President Obama said four years ago that he would helm "the most transparent administration in history"? So much for that.

I'm amazed that so few Americans - most notably, so few liberals - have protested his secretive remote-control assassination program. Drones have killed roughly 3,000 people in Yemen and Pakistan, including collateral-damage civilians, but the actual numbers are secret. So is the process. We don't know anything about the rules of engagement, how people wind up on Obama's hit list, who reviews the evidence, and what criteria are applied to that evidence.

The Fifth Amendment to the Constitution states that "No person shall be ... deprived of life ... without due process of law." Drones are inimical to due process. It would be nice to know how the administration's lawyers have addressed that conundrum in legal memos. Those memos exist, but they remain classified. The Obama team is reportedly writing rules for itself, a set of standards and procedures, but we may never know whether these rules are scrupulously followed, or even what they are.

Back in May 2009, Obama vowed that his national security actions would be transparent, so that Americans could "make informed judgments and hold us accountable." But nearly four years and hundreds of drone strikes later, his actions bring to mind the remark Michael Corleone utters near the end of The Godfather Part II: "If anything in this life is certain, if history has taught us anything, it's that you can kill anybody."

Granted, we're waging a global shadow war against bad actors who don't wear uniforms. Drones often kill known terrorists who might otherwise murder innocent Americans. No weapon is flawless. And in war, even the good guys inadvertently kill civilians; during the D-Day invasion, the Allies killed an estimated 12,000 French and Belgian civilians who lived close to Nazi-controlled railroads.

But if George W. Bush were whacking thousands of foreigners (plus a few American citizens) using a hit list shrouded in secrecy, in apparent violation of the Fifth Amendment and in blatant violation of transparency promises, rest assured that liberal Democrats would be holding hearings and denouncing him on MSNBC.

They don't seem disturbed, however, that Obama has tripled down on Bush's nascent drone program, and that this president is doing so on the fly and in secret. Their partisan instincts appear to be trumping adherence to principle. But all presidents, regardless of party, need to be held accountable.

Speaking of drones on The Daily Show in October, Obama said that "one of the things we've got to do is put a legal architecture in place ... to make sure that not only am I reined in, but any president is reined in." It was a scary remark: It suggested that Obama has been waging unchecked war without that legal basis - with nothing to rein him in.

We don't know what we don't know. Obama said in September that the drones target known terrorists who pose "an imminent threat to the United States" (allowing us to invoke the doctrine of self-defense), but "imminent" appears to be a slippery term. Obama has reportedly authorized the use of drones in what the CIA calls "signature strikes" - those conducted against unidentified people who brandish guns in regions where militants are strong. In other words, drones are sometimes used preemptively, to kill those who might be a threat in the future. Obama is judge, jury, and executioner.

But who cares, right? This is all happening far away, to Muslims we will never know. Many liberals are fine with it because Obama is one of them, and many conservatives are mute because they know there's no percentage in attacking a president for being too tough on terrorism. That also explains why Congress hasn't lifted a finger to conduct any oversight. And most Americans would probably rather watch football than weigh the implications of drone warfare.

At least a few million Americans have also been watching the hot cable show Homeland, which is all about the unintended domestic consequences of a drone attack. The Showtime series features a hawkish vice president, in cahoots with the CIA, who authorizes a drone strike that destroys a Muslim school and kills the son of a known terrorist. The terrorist retaliates by plotting acts of revenge on American soil. Yeah, it's just a TV show, but Homeland prompts the viewer to consider whether drones might inspire blowback and perpetuate the cycle of violence.

So, at a minimum, let's ask: Is Obama authorized to kill anybody? Under what criteria? What's in the legal memos? How is the evidence weighed? What checks and balances have been established to ensure that drones are not abused by this president and those to follow?

We don't really know whether drones are the answer in the war against terrorism. But more of us should at least ask the questions.