There are two ways to try to deter hostile regimes from attacking their neighbors.
Primary responsibility for the war in Ukraine belongs, of course, to Russia and Vladimir Putin, who invaded a neighbor without a shred of justification — a neighbor that posed no real-world threat to Russia’s borders or its people. That said, it is entirely fair to look at the mistakes by other actors that led to this pass. On this much, there should be common agreement: Strategic ambiguity failed to deter Russian aggression. That should compel some hard thinking about our Taiwan policy.
There are two ways to try to deter hostile regimes from attacking their neighbors. One is to draw clear red lines: Go past this point, and you will face particular consequences. Of course, as we saw with Barack Obama’s laughable Syria policy, drawing clear red lines is ineffective if you don’t enforce them. Indeed, this was a major backdrop to the Iraq War: Saddam Hussein was regularly violating the terms of the cease-fire that ended the Gulf War, and the George W. Bush administration had to decide whether to enforce those terms or admit that we were abandoning them.
The other way is strategic ambiguity: Leave the hostile regime guessing what exactly will trigger a response, and what kind of response it will be. That can be a more effective approach if your own leader seems belligerent and unpredictable, which is why a majority of Americans think Putin would not have invaded Ukraine when Donald Trump was president.
The United States and its NATO allies could have made things clear to Putin and Russia. We could have accepted Ukraine into NATO. We could have explicitly threatened some of the things we are doing now — sending weapons to Ukraine, cutting off Russian oil and gas. We did not. Nor did we close the door on accepting Ukraine into NATO, or tell Putin that we would not go to war over Ukraine — steps that could have encouraged Putin but also allayed some of his paranoia. Strategic ambiguity can be the best of both worlds, leaving us flexibility and cowing our enemies without making commitments we don’t want to back up. But it can also be the worst of both worlds, leaving the bad actors to take a reckless gamble — especially if they judge our leaders to be weak and feckless, as Joe Biden has particularly appeared to be since the surrender of Afghanistan. That has sometimes been the outcome of ambiguity in the past: The Gulf War and the Korean War both followed U.S. diplomats’ failing to make clear our willingness to defend the targeted country. Germany in the First World War similarly gambled that British ambiguity on the defense of Belgium was bluff. Russia made the same miscalculation about British and French defense of the Ottoman Empire in 1853, leading to the Crimean War.
This time, it didn’t work. Putin saw what he judged to be a bluff, and called it, leading to a bloody war.
In Taiwan, strategic ambiguity has been U.S. policy for decades: We will not tell Communist China or Taiwan whether or not we would defend the island if China attacks. So long as America is run by people the Chinese leadership fears, that can work, and it has worked for decades. But Xi Jinping is doubtless closely watching Ukraine. If he concludes that ambiguity did not stop Putin from rolling over Ukraine, he may draw his own conclusions about Taiwan. And that will put the United States and its Asian allies to some hard choices about whether to drop the ambiguity.