President Obama’s recent refusal to describe his use of force “doctrine” is perfectly explainable: he does not have such a doctrine. But he needs one, and he needs it sooner rather than later.

As the administration prepares the release of a new National Security Strategy, America’s geopolitical friends and foes alike will look for answers to a crucial question: what is America’s post-Iraq “use of force” doctrine? Or, in other words, what are the strategic threats to our national security interests that would lead this administration to decisively use America’s still formidable military power? Establishing a use of force doctrine can reassure our allies, guide military contingency planning, and, most importantly, go a long way in deterring would-be aggressors like Vladimir Putin from actions detrimental to our interests. 

After the fall of the Berlin Wall, President George H.W. Bush established the pillars of America’s post-Cold War use of force doctrine by committing U.S. forces to deter and punish military aggression in three strategic regions deemed vital to our interests: Europe, East Asia, and the Persian Gulf. His successors, Bill ClintonWilliam (Bill) Jefferson ClintonThe case for a ‘Presidents’ Club’ to advise Trump After FBI cleared by IG report, GOP must reform itself Bill Clinton hits Trump administration policy separating immigrant families in Father's Day tweet MORE and George W. Bush, also embraced this commitment to militarily undergird the current international order in these three regions, in partnership with our local allies. But for the war in Afghanistan, all of America’s other post-Cold War major military interventions (the two wars in Iraq and the Balkan wars) took place at least in part to defend the current order favorable to US interests.

In contrast, Obama’s words and actions since taking office cast serious doubts on his willingness to go to war in defense of U.S. interests in these key regions. This departure from the old doctrine, however, was not followed by explicitly proclaiming a new vision for the use of force more in tune with this administration’s worldview. Claiming that the “tide of war is receding” and that we won’t rush to the use of force is not a doctrine. Nor is simply insisting that military aggression is “unacceptable” by the international community in the  21st century, as Secretary Kerry repeatedly claimed in recent weeks. This lack of a clear doctrine on when Obama will use (or threaten to use) force eventually led to an uncertain pattern of behavior when faced with military crises in Libya, Syria, and now Ukraine; it also brought further uncertainty to an already tensed situation along the East Asian littoral.  

Defenders of the president contend that Obama’s response to military aggression by economic sanctions and diplomatic pressure is the appropriate one in today’s international system. This argument misses how important the use of American military power remains in making credible America’s commitments to regional stability and to its allies. As political scientist Henry Nau showed in a recent book, without the threat of force to back it up American diplomacy is toothless and the deterrent effect of the president’s “red lines” is minimal.  Obama may prefer to rely on non-military tools, but the hard truth is that there are certain issues in world politics where there is still no substitute for the use (or threat) of force. Economic sanctions and diplomatic isolation, as witnessed in the cases of Iran and Russia, are at best limited tools of statecraft whose impact takes a long time to produce results. Moreover, their ultimate effectiveness is dubious on “hard power” matters like nuclear proliferation or military aggression.  

What should Obama’s use of force doctrine say? The president has two broad options, each with its own set of risks and rewards.

The first option is to renew America’s post-Cold War commitment to maintain the status quo in the three areas of major geostrategic importance mentioned above. This will require him to proclaim his willingness to use force together with our NATO, Persian Gulf or East Asian allies to deter any would-be regional aggressor from upending the current balance of power. Such a doctrine requires a higher level of defense spending than currently planned for. It would also require the President to spend the political capital necessary to persuade a skeptical public that the benefits of supporting the US dominating security position in Europe, East Asia, and the Persian Gulf are worth the costs.   

If Obama is unwilling to embrace the activist doctrine of his predecessors, a second option is to limit U.S. military interventions to responding to a direct attack on a formal American ally. Such a shift in America’s strategy poses higher risks to our economic and national security interest in regional peace, but it is more in line with the President’s focus on reducing defense spending and limiting foreign interventions. The downsides are that this might invite aggression in areas left outside the US formal alliance system. But, that would still be preferable to the current situation in which the administration’s ambitious rhetoric of “red lines” and “serious consequences” is at odds with its unwillingness to use the military means necessary to back it up.

Either one of these two choices is better than no doctrine at all. The Obama administration’s upcoming NSS document is the perfect opportunity to bring some much-needed coherence to its ad-hoc conduct on the use of force.

Popescu, PhD, is an assistant professor at the Robertson School of Government, Regent University.