I’ve been asked a lot recently about the President’s power under Article II to order a military strike on North Korea in the absence of congressional authorization. The proper meaning of Article II on this question is contested and I won’t offer my views on that here. But the only opinion about Article II that effectively matters on this question is the Executive branch’s. The Executive branch will decide for itself whether to act unilaterally and neither the People nor the other two branches can do much in advance, at least as a legal matter, to stop it. So what is the Executive branch view of a strike on North Korea?

Some might think that the place to look for guidance is OLC’s latest word on war powers, a 2011 OLC opinion on the unilateral use of force in Libya. But that opinion is not the most relevant or necessarily even controlling, since it did not address a situation involving self-defense. The Libya operation was primarily justified on the grounds of preserving regional stability and upholding a U.N. Security Council Resolution. Self-defense is more at the core of presidential power, and easier to justify under Article II.

To be sure, the 2011 opinion suggested that a president might not be able to use force unilaterally if the force involved “prolonged and substantial military engagements, typically involving exposure of U.S. military personnel to significant risk over a substantial period.” In that situation, OLC reasoned, the president might be starting a “war” that (according to OLC) Congress might have to approve under Article I of the Constitution. But that standard can be skirted in the Korea situation. We know from the experience in Libya itself that hundreds of bombing sorties over many months resulting in the removal of power of a foreign leader (Muammar Qaddafi) does not require congressional approval. (I assume here that the Obama administration believed the Libya operation was lawful to the end.) That gives the president leeway in Korea even under the 2011 opinion, although the likelihood of escalation is relevant under the 2011 opinion and surely operates differently in Korea. Much more importantly, the Article I limitation announced in the 2011 opinion was very tentative: OLC said only that Article I was a “possible” constitutional limitation, and that a substantial military engagement “may” require congressional authorization. OLC did not rule or hold that Article I applies in this context.

Another reason the 2011 opinion is not terribly relevant when it comes to the Korea situation is that there are extant OLC opinions that are much more on point. Early in the George W. Bush administration, OLC wrote two legal opinions that collected and extended a lot of Executive branch precedents and thinking on the president’s power to use force in the national interest, including self-defense and anticipatory self-defense. The first is a September 25, 2011 opinion on using force against terrorists and nations that support them, and the second is an October 23, 2002 opinion to use force against Iraq. The Obama administration’s OLC rescinded many Bush-era OLC opinions. It did not rescind these two. Both remain on the books and are valid OLC sources of authority

I won’t summarize these opinions in detail; I urge readers to look at them in their entirety. Suffice it to say that the opinions are more on point than the 2011 opinion, and that OLC takes a very different approach to Article I limits (they reject any such limits, even “possible” ones). And—citing historical practice and precedent—these two opinions reach very broad conclusions about presidential power under Article II to use force to protect national interests, especially the defense of the nation.

The 2001 opinion is focused on meeting terrorist threats, but it collects and reads charitably all significant precedents on unilateral uses of force, and concludes (with my emphasis added):

In light of the text, plan, and history of the Constitution, its interpretation by both past Administrations and the courts, the longstanding practice of the executive branch, and the express affirmation of the President's constitutional authorities by Congress, we think it beyond question that the President has the plenary constitutional power to take such military actions as he deems necessary and appropriate to respond to the terrorist attacks upon the United States on September 11, 2001. Force can be used both to retaliate for those attacks, and to prevent and deter future assaults on the Nation. Military actions need not be limited to those individuals, groups, or states that participated in the attacks on the World Trade Center and the Pentagon: the Constitution vests the President with the power to strike terrorist groups or organizations that cannot be demonstrably linked to the September 11 incidents, but that, nonetheless, pose a similar threat to the security of the United States and the lives of its people, whether at home or overseas. In both the War Powers Resolution and the Joint Resolution, Congress has recognized the President's authority to use force in circumstances such as those created by the September 11 incidents. Neither statute, however, can place any limits on the President's determinations as to any terrorist threat, the amount of military force to be used in response, or the method, timing, and nature of the response. These decisions, under our Constitution, are for the President alone to make.

The 2002 opinion is briefer on the issue of unilateral use of force against Iraq under Article II. It concludes (again, with my emphasis):

Accordingly, we believe that the President’s constitutional authority to undertake military action to protect the national security interests of the United States is firmly established in the text and structure of the Constitution and in executive branch practice. Thus, to the extent that the President were to determine that military action against Iraq would protect our national interests, he could take such action based on his independent constitutional authority; no action by Congress would be necessary. For example, were the President to conclude that Iraq’s development of WMD might endanger our national security because of the risk that such weapons either would be targeted against the United States, or would be used to destabilize the region, he could direct the use of military force against Iraq to destroy its WMD capability. Or, were it the President’s judgment that a change of regime in Iraq would remove a threat to our national interests, he could direct the use of force to achieve that goal. Were the President to take such action, he would be acting consistent with the historical practice of the executive branch.

OLC added, in a footnote to this paragraph’s penultimate sentence: “These examples are intended to be illustrative and non-exclusive.”

There is a lot to quibble with in these opinions, and these conclusions are indeed very broad. But reading the opinions will make plain that the Executive has been asserting more and more authority to use force unilaterally, including in self-defense, for many decades. They also make plain that the President’s unilateral military powers are at their apex when defense of the nation is at stake.

North Korea has already taken many more threatening actions against the United States, and uttered many more threatening words, than did Iraq. Both the 2001 and 2002 opinions, and some of the precedents they cite, could easily be invoked in support of a self-defensive strike on North Korea. We on the outside can question the validity of these opinions. And one can urge OLC not to consider them. But an Executive branch lawyer cannot simply discard prior legal opinions willy-nilly. An OLC lawyer asked about the president’s authorities to strike North Korea would have to take these opinions (and the precedents and opinions they cite) into account unless the office was prepared to overrule them, which is a very high bar. If the President and his military advisors decide that a military action against North Korea is the best course of action to protect the nation, it is unrealistic in the extreme to expect OLC to discard these opinions (and the underlying precedents) and say “no.” The much more likely scenario is that OLC will write the opinion without much trouble. That is the reality of executive branch lawyering in the war powers context, especially when the stakes are so high and the legal opinions (including ones beyond the 2001 and 2002 opinions) so promiscuously broad. It is a reality that did not begin with the Trump administration.

In short, as I argued recently in a different context, don’t expect the law or lawyers to provide avenues to constrain the President from using force in North Korea if the President deems it the appropriate course.