Though Moscow now appears willing to talk about Ukraine, it is far from clear that Russia’s terms will be acceptable to the United States—or, more important, to Kiev. Meanwhile, according to NATO’s commanding General Philip Breedlove, Russia’s troops could seize southern and eastern Ukraine within three to five days. With such high stakes, it’s time to reexamine some of our fundamental assumptions about war.

Nineteenth-century American humorist Josh Billings—a contemporary and rival of Mark Twain—is credited as the originator of the often-cited warning that “it ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so.” Unfortunately, after two decades of sole-superpowerdom, our president, politicians and pundits seem to know a great deal that ain’t so about wars. Thus as Washington debates its response to Russia’s annexation of Crimea, all sides agree on only one thing: America will not go to war with Russia. Unfortunately, their certainty may rest upon a series of dangerously false assumptions.

Most assume that as the world’s preeminent military power, the United States gets to choose whether it goes to war or not. After two major wars in Afghanistan and Iraq, plus interventions in the Balkans and Libya and a decision to skip Syria, Americans have become accustomed to the idea that we can comfortably discuss our military options while others wait because none would dare challenge us. Though Leon Trotsky was wrong about everything else, policymakers should remember his statement that “you may not be interested in war, but war is interested in you.”

Would Russia directly attack U.S. forces or other targets? This is unlikely, as America’s military is far more powerful than Moscow’s—something Russian officials admit. Nevertheless, the fact that Russia’s President Vladimir Putin has correctly calculated that the United States would not respond militarily to his actions so far does not mean that he will continue to be correct indefinitely in judging how far he can go. He knows more than a little that isn’t so himself.

This connects directly to a second assumption: that we, Putin, the European Union, Ukraine’s new government and Crimean leaders can collectively control or manage events. The collapse of the February 21 agreement between ousted Ukrainian president Viktor Yanukovych and his opponents-turned-successors demonstrates unmistakably that this is untrue—the deal fell apart because protestors on the Maidan demanded Yanukovych’s immediate removal when the U.S., the EU and the leaders of the Ukrainian opposition were all on board with the agreement and when Putin and Crimea’s leaders would have reluctantly accepted it. Yanukovych fled Kiev and Ukraine because he feared the mob, not establishment opposition leaders.

The relative absence of violence in Crimea has been remarkable. Conditions in eastern and southern Ukraine have been more troubling, and could get worse. How long can the current relative calm last? If demonstrations and counterdemonstrations devolve into violence, might Russia intervene elsewhere in Ukraine? What would NATO do if Ukraine’s weak army and paramilitary groups resisted? Where is the border between eastern Ukraine and western Ukraine? Would Russia’s general staff knowingly create a Pakistan-style haven for irregular fighters in western Ukraine by stopping their advance at that arbitrary point? Might Moscow attack the arms shipments some advocate or escalate in other ways? Carl von Clausewitz noted that once a war starts, it has its own logic of relentless escalation to extremes. We forget this at our peril.

Many prefer “crippling” sanctions, arguing that draconian economic measures could force Moscow to change course, or just inflict a devastating cost, while avoiding armed conflict. This popular view rests on a third assumption: that sanctions are an alternative to war rather than a prelude to it. Iran, Iraq, North Korea and some others have been prepared to absorb sanctions without attempting armed retaliation—but none is a major power. The last time the United States imposed crippling sanctions on another major power was in 1940–41, when Washington ratcheted up restrictions on trade with Imperial Japan, culminating in a de facto oil embargo and including bans on exports of iron, steel, copper and other metals as well as aviation fuel. Though President Franklin Delano Roosevelt was concerned about provoking Japan, U.S. officials thought that it would be irrational for Tokyo to attack the United States. Japanese leaders saw giving in to Washington as a greater danger. How would Putin respond to similar pressures?

Some take comfort in a critical difference between 1941 and 2014—the United States and Russia are nuclear superpowers. They assume that since nuclear deterrence succeeded in preventing U.S.-Soviet conflict during the Cold War it will do so again. But are Barack Obama and Vladimir Putin prepared to use nuclear weapons? More important, does each believe that the other could use nuclear weapons in an escalating conventional conflict over Ukraine? If either leader believes that the other will flinch, nuclear deterrence of conventional war could suddenly fail. Nuclear deterrence of conventional escalation could also fail. Moscow has already been waving its nuclear card.

Avoiding a war while resolutely defending U.S. national interests—and deterring Russia’s further intervention in Ukraine—requires a policy starkly different from the Obama administration’s. Greater resolve is essential, but there is also a fine balance between deterrence and provocation. President Barack Obama’s statement in Europe that Russia cannot be “deterred from further escalation by military force” is especially dangerous because it abandons a central foundation of post-World War II American strategy—the idea that U.S. dominance at each stage in a potential escalation chain deters conflict. From this perspective, Mr. Obama may be our first true post-Cold War president. Too bad that neither America nor the rest of the world may be quite ready for him.

Paul J. Saunders is Executive Director of the Center for the National Interest. He was a State Department Senior Advisor in the George W. Bush Administration. Follow him on Twitter: @psaunderscftni.

Image: Wikimedia Commons/Vitaly V. Kuzmin/CC by-sa 3.0

The above first appeared in April 2014. It is being reposted due to reader interest.