President Obama speaks about his administration's drone and counterterrorism policies. (Saul Loeb/AFP/Getty Images)

President Obama's speech Thursday detailing a new approach to counterterrorism focused heavily on the use of unmanned aerial vehicles, better known as drones. Though he explained new policies to curtail their use, bolster oversight and institutionalize rules and norms for how and when to target enemies abroad, Obama also defended his administration's practice of using drones in Africa, the Middle East and South Asia.

The Obama administration's case for drones, as articulated in Thursday's speech, seems to boil down to three points: (1) Terrorists are "continuously trying to kill people" in the United States and must be stopped; (2) Some local governments "cannot or will not" stop those terrorists; (3) Drones are the least bad option for stopping these terrorists.

There are some premises in that case that could certainly be disputed (to be clear, that doesn't make them necessarily wrong) but first, here's his case in his own words.

1) Terrorists are "continuously trying to kill people" in the United States and must be stopped.

We were attacked on 9/11. Within a week, Congress overwhelmingly authorized the use of force. Under domestic law and international law, the United States is at war with al-Qaeda, the Taliban, and their associated forces. We are at war with an organization that right now would kill as many Americans as they could if we did not stop them first. So this is a just war – a war waged proportionally, in last resort, and in self-defense.

(2) Some local governments "cannot or will not" stop those terrorists.

But despite our strong preference for the detention and prosecution of terrorists, sometimes this approach is foreclosed. Al-Qaeda and its affiliates try to gain a foothold in some of the most distant and unforgiving places on Earth. They take refuge in remote tribal regions. They hide in caves and walled compounds. They train in empty deserts and rugged mountains.

In some of these places – such as parts of Somalia and Yemen – the state has only the most tenuous reach into the territory. In other cases, the state lacks the capacity or will to take action.

(3) Drones are the least bad option for stopping these terrorist.

As I’ve said, even small Special Operations carry enormous risks. Conventional airpower or missiles are far less precise than drones, and likely to cause more civilian casualties and local outrage. And invasions of these territories lead us to be viewed as occupying armies; unleash a torrent of unintended consequences; are difficult to contain; and ultimately empower those who thrive on violent conflict. So it is false to assert that putting boots on the ground is less likely to result in civilian deaths, or to create enemies in the Muslim world. The result would be more U.S. deaths, more Blackhawks down, more confrontations with local populations, and an inevitable mission creep in support of such raids that could easily escalate into new wars.

On the first point, Obama does engage with the idea that non-lethal means could stop foreign-borne terrorist plots (he discusses a "war of ideas" to dissuade potential terrorist recruits, for example). But he seems to take as a given that, in the hypothetical absence of a specifically lethal response, more terrorists will succeed. The question of how many more is not something I know how to answer, although it's worth noting that proactive intelligence gathering has foiled a number of plots, such as the 2010 effort by Yemen-based terrorists to ship bombs to the U.S. in printer cartridges.

The second point seems the most straightforward: The Pakistani government, which has tried and failed to uproot some terrorist groups and is frequently accused of tolerating others, is probably not going to reliably serve all U.S. counterterrorism needs on its own. While Obama nodded his head to efforts by Pakistan and other governments and mentioned efforts to help them, he's probably not wrong to assume that, for the time being, the U.S. is going to have to take an active role working against foreign terrorists.

Obama's third point, that drones are preferable to all other lethal actions, is perhaps more complicated than it at first sounds. Not because a full-on invasion of southern Somalia would be a great idea, but because the costs of a drone-led strategy are considerable. Obama spends a great deal of time in the speech weighing these costs against the benefits of drones, which he acknowledges raise questions "about who is targeted, and why; about civilian casualties, and the risk of creating new enemies; about the legality of such strikes under U.S. and international law; about accountability and morality."

While he engages with each of these downsides, he lays out his implicit case for drones most directly when discussing civilian casualties:

This last point is critical, because much of the criticism about drone strikes – at home and abroad – understandably centers on reports of civilian casualties. There is a wide gap between U.S. assessments of such casualties and non-governmental reports. Nevertheless, it is a hard fact that U.S. strikes have resulted in civilian casualties, a risk that exists in all wars. For the families of those civilians, no words or legal construct can justify their loss. For me, and those in my chain of command, these deaths will haunt us as long as we live, just as we are haunted by the civilian casualties that have occurred through conventional fighting in Afghanistan and Iraq.

But as commander-in-chief, I must weigh these heartbreaking tragedies against the alternatives. To do nothing in the face of terrorist networks would invite far more civilian casualties – not just in our cities at home and facilities abroad, but also in the very places – like Sana’a and Kabul and Mogadishu – where terrorists seek a foothold. Let us remember that the terrorists we are after target civilians, and the death toll from their acts of terrorism against Muslims dwarfs any estimate of civilian casualties from drone strikes.

Although there's a complexity to Obama's moral case for drones, it reduces down to a binary: Using drones can kill civilians, but not using them would lead to even more civilians being killed. There are many, many more moral, ethical and legal issues related to drones, some of which are in the speech and some of which aren't. And there is a wide range of gray areas in how they're implemented, against whom, under what circumstances and what guidelines. But it's this basic proposition – taking lives to save others – that seems at the heart of Obama's case.