Tens of thousands of Russian troops are positioned near Ukraine.
Ukraine says Russia may be preparing for an attack. American officials have increasingly expressed concern about the scale and nature of Russia’s military activity. Moscow denies that it is planning an invasion and argues that it is entitled to move troops within its own territory. President Vladimir Putin, meanwhile, is demanding guarantees that NATO will not continue expanding eastwards towards Russia.
Nobody outside a relatively small group inside the Russian government can know with certainty what Putin actually intends to do.
That uncertainty is precisely what makes the situation dangerous.
If Russia were obviously going to invade Ukraine tomorrow, the political problem would be clearer. Western governments would have to decide how to deter or respond to an attack.
If Russia were obviously conducting an ordinary military exercise, there would be much less reason for alarm.
Instead, Russia has created something in between: enough military capability to make an attack plausible while leaving its intentions uncertain.
That ambiguity is not necessarily a failure of Russian strategy.
It may be the strategy.
Military forces do not have to cross a border to produce political effects. If Ukraine believes an invasion is possible, Kyiv has to prepare for one. If NATO governments believe an invasion is possible, they have to discuss sanctions, military assistance and diplomacy. If financial markets believe war is possible, risk calculations change.
Russia therefore gains leverage from the possibility of force before using force at all.
This is coercive diplomacy: changing another actor’s behaviour by convincing them that refusing your demands may produce a much worse outcome.
The difficult question for the United States and Europe is how seriously to take the threat without making conflict more likely themselves.
Russia’s relationship with Ukraine did not suddenly become hostile this month. In 2014, after Ukraine’s pro-Russian president Viktor Yanukovych fled following the Maidan protests, Russia seized and annexed Crimea. War then began in eastern Ukraine between Ukrainian forces and Russian-backed separatists. The conflict has never fully ended.
The Minsk agreements were supposed to create a political pathway out of the war in the Donbas. They have not produced a lasting settlement.
Ukraine has meanwhile moved politically closer to the West and continues to seek eventual NATO membership.
For Russia, that possibility is deeply threatening.
For Ukraine, Russia’s insistence that Ukraine should not join NATO is itself deeply threatening.
That creates a security dilemma in almost perfect form.
Ukraine looks at what happened in Crimea and the Donbas and concludes that it needs stronger Western security relationships because Russia may attack it.
Russia looks at Ukraine’s growing relationship with NATO and concludes that it needs to apply greater pressure because Western military influence is moving towards Russia’s borders.
Ukraine interprets the Russian pressure as proof that it was right to seek NATO support.
Russia interprets the increased NATO support as proof that its original fear was justified.
Each side’s attempt to become safer makes the other side feel less safe.
That does not mean responsibility is equal.
Russia annexed Ukrainian territory in 2014. Ukraine has not annexed Russian territory. Ukraine is internationally recognised as a sovereign state and therefore has a strong legal argument that its foreign-policy choices belong to Ukraine, not Moscow.
But understanding why Russia perceives NATO expansion as threatening is not the same thing as accepting that Russia therefore has a right to determine Ukraine’s alliances.
This distinction between explanation and justification keeps appearing in international politics.
If we refuse to understand an adversary’s security concerns because we believe their behaviour is wrong, we make deterrence harder. Successful deterrence requires understanding what the other actor values and fears.
But understanding those fears cannot automatically become giving the other actor what it wants.
Otherwise military threats become an extremely effective way of obtaining political concessions.
That creates the central dilemma facing NATO.
Putin wants guarantees limiting further NATO expansion, particularly towards Ukraine.
Why not simply promise that Ukraine will never join?
One argument is pragmatic. Ukraine is not currently close to NATO membership anyway. Several NATO governments are reluctant to admit a country already involved in an unresolved conflict with Russia. A formal promise could therefore concede something that is unlikely to happen soon in exchange for reducing the immediate risk of war.
But the cost would be enormous.
It would effectively give Russia influence over the foreign policy of a neighbouring sovereign country.
Ukraine would learn that enough Russian military pressure can cause Western governments to negotiate limits on Ukrainian choices without Ukraine controlling the outcome.
Other countries would notice too.
That is why credibility matters.
Foreign policy is rarely only about the immediate transaction. Governments ask what precedent today’s concession creates for tomorrow’s negotiation.
Suppose Russia places 100,000 troops near a neighbour and receives a major geopolitical concession.
What incentive has the international system created?
Perhaps Russia concludes that coercion works.
Perhaps other powerful countries reach the same conclusion.
On the other hand, refusing every concession because concessions might reward coercion can make diplomacy impossible.
Sometimes adversaries have genuine security interests that need accommodation.
The challenge is distinguishing compromise from capitulation.
There is no mathematical formula for doing that.
This is where deterrence becomes more complicated than simply threatening punishment.
Western governments are considering severe economic sanctions if Russia attacks Ukraine. The United States can also provide military equipment and intelligence to Kyiv and reinforce NATO members in Eastern Europe.
The objective is to change Putin’s calculation before an invasion occurs.
In simplified terms, Russia attacks if Putin believes:
Expected benefit of attacking > expected cost of attacking.
Deterrence therefore works by altering either side of that inequality.
Reduce the expected benefit through stronger Ukrainian defences.
Increase the expected cost through sanctions and diplomatic consequences.
But this framework immediately creates another problem: policymakers do not know exactly what Putin values.
If he believes preventing Ukraine’s permanent integration with the West is an existential Russian security interest, sanctions that appear enormous in Washington may appear tolerable in Moscow.
Deterrence is not determined by how painful we think a punishment is.
It is determined by how painful the other side expects it to be relative to what they believe they gain.
That is why understanding an adversary is so important.
Not because their worldview is correct.
Because their worldview determines their behaviour.
There is also the question of credibility.
Threatening sanctions is easy.
Convincing Russia that those sanctions will actually be imposed is harder.
European countries have different economic relationships with Moscow. Germany and other states rely significantly on Russian energy. The Nord Stream 2 gas pipeline connecting Russia directly to Germany has become particularly politically sensitive.
Russia can therefore ask whether Western unity would survive the economic costs of a serious confrontation.
This gives Europe a collective-action problem.
Every NATO government may prefer that Russia be deterred.
Individual governments may still prefer that somebody else bears more of the economic cost.
Russia has reasons to exploit those differences.
Alliance cohesion is therefore itself part of deterrence.
A sanction does not need to have been imposed yet to matter. If Moscow believes Europe will remain united enough to impose it, the expected cost enters Russia’s calculation today.
If Moscow believes European governments will argue until the threat becomes meaningless, deterrence weakens before anybody signs a sanctions document.
Information and expectations again become forms of power.
Ukraine also has agency in this story, which risks disappearing whenever Russia and America begin talking about European security.
This cannot simply become another negotiation between Washington and Moscow over what happens to a smaller country located between them.
Ukraine has more than forty million people, its own government and its own political preferences.
The principle sometimes expressed as “nothing about Ukraine without Ukraine” matters because great powers have a long history of treating smaller states as geographical buffers rather than political communities.
From Moscow’s perspective, Ukraine’s location makes it strategically important.
From Ukrainians’ perspective, that same geography should not eliminate their right to make political choices.
This is one of the permanent tensions between realism and sovereignty in international relations.
Realism says geography and power matter whether we like them or not. A major power will naturally care intensely about military alliances near its borders.
International law says sovereign states possess the right to choose their own political and security relationships.
Both describe something real.
The mistake would be assuming that because power affects what choices are feasible, power therefore determines what choices are legitimate.
Russia may possess enough military power to constrain Ukraine’s options.
That does not automatically create a right to do so.
There is another historical complication: NATO expansion itself.
After the Cold War, NATO expanded eastwards to include countries that had previously been inside the Soviet sphere of influence, including Poland, Hungary, the Czech Republic and later the Baltic states.
Russian leaders have long argued that this expansion threatens their security.
Western governments respond that NATO is a defensive alliance and that countries in Central and Eastern Europe actively sought membership because they feared Russia.
Again, the same action has two interpretations.
Poland sees NATO membership as protection from Russia.
Russia sees NATO membership in Poland as NATO moving closer to Russia.
Neither perception is imaginary.
The problem is that security cannot always be increased for one side without affecting the other.
This is why I think the phrase “NATO expansion” can itself be misleading.
From Moscow, it looks like NATO expanded eastwards.
From Warsaw, Tallinn or Vilnius, those countries chose to join.
The verb changes depending on where you stand.
That does not resolve the dispute, but it changes how we understand it.
Eastern European countries were not empty territory absorbed by an advancing organisation. Many actively wanted membership because their historical experience of Russian and Soviet power made Western security guarantees attractive.
Ignoring their agency reproduces exactly the great-power politics they were trying to escape.
At the same time, Western governments should be capable of acknowledging that a military alliance approaching another major power’s borders will affect that power’s threat perception.
Again: explanation without justification.
The most dangerous possibility is miscalculation.
Perhaps Putin does not currently intend to invade.
He may be using military mobilisation to obtain diplomatic concessions.
But coercive strategies create their own risks.
Once tens of thousands of troops, equipment and commanders are positioned near a border, the cost of moving from threat to action falls.
Political leaders can also become trapped by their own rhetoric.
If Putin makes demands publicly and NATO rejects them completely, withdrawing the forces without obtaining anything may look like weakness domestically.
The threat then creates pressure to follow through.
This is one reason signalling matters so much in international crises.
Governments need ways to compromise without making the other side appear humiliated.
That can sound morally unsatisfying. Why should Western governments care whether Putin can save face after creating the crisis?
Because the objective of diplomacy is not awarding moral points.
It is preventing outcomes that leave everyone worse off.
Giving an adversary an off-ramp is not necessarily rewarding them. Sometimes it is how coercive crises end without war.
But the off-ramp cannot be so generous that creating the crisis becomes profitable.
Again, the line between compromise and capitulation.
The United States and Russia therefore need communication precisely because they distrust one another.
Biden and Putin are expected to speak directly. That does not mean Washington is legitimising Russian threats. It means nuclear-armed states with military forces operating around the same region should probably understand one another’s red lines before somebody crosses one accidentally.
I wrote after their Geneva summit in June that diplomacy does not always resolve disagreement. Sometimes it makes disagreement manageable.
This may be exactly such a case.
The ideal outcome is extremely undramatic.
Russia does not invade.
Ukraine remains sovereign.
NATO does not enter a military confrontation with Russia.
Diplomatic discussions continue.
Perhaps some confidence-building measures reduce tensions.
If that happens, there will be no photograph of victory because the successful outcome is an event that doesn’t occur.
That creates the same political problem as pandemic prevention. Successful deterrence is difficult to observe.
If Russia withdraws without attacking, critics may say the threat was exaggerated.
Perhaps it was.
Or perhaps deterrence worked.
We can rarely observe the counterfactual.
That makes governments vulnerable to both overreaction and complacency.
Act too aggressively and you may escalate a threat that was partly bluff.
Act too weakly and you may convince the other side that aggression is cheap.
The correct response has to communicate two messages simultaneously:
An attack will be extremely costly.
There remains a diplomatic path that avoids those costs.
Deterrence without diplomacy can become escalation.
Diplomacy without deterrence can become appeasement.
The two are complements, not opposites.
As of tonight, I don’t know whether Russia intends to invade Ukraine.
That uncertainty is not a weakness in the analysis.
It is the central fact policymakers have to work with.
We should resist the temptation to turn possibilities into predictions simply because predictions make political commentary sound confident.
Russia has created the capability for a much larger military operation.
That matters.
American and Ukrainian warnings deserve serious attention.
Russia also denies that it intends to invade.
That claim should not simply be accepted, particularly after what happened in Crimea in 2014.
But neither should an invasion be treated as inevitable before it occurs.
Policy has to operate in the space between those conclusions.
Perhaps this is what makes international politics so difficult. Governments rarely respond to things that have already happened. They respond to estimates of what other governments might do.
Military forces are moved because of possibilities.
Sanctions are threatened because of probabilities.
Alliances are built around future scenarios.
And every response changes the probability it was designed to address.
If NATO strengthens Ukraine, Russia may be deterred.
Or Russia may feel more threatened.
If NATO offers concessions, Russia may de-escalate.
Or it may conclude pressure works.
There is no move that leaves the strategic environment unchanged.
The challenge is therefore not predicting Putin’s mind with certainty.
It is constructing a situation in which, whatever his current preference, choosing not to invade remains more attractive than choosing to invade.
That is deterrence.
And if it succeeds, the most important political event of this crisis will be something none of us ever gets to see.
