When I wrote about Russia and Ukraine in early December, the central problem was uncertainty. Russia had assembled substantial military forces near Ukraine, American and Ukrainian officials were warning that Moscow might be preparing for an offensive, and Vladimir Putin was demanding guarantees that NATO would stop expanding eastwards. Russia denied planning an invasion, and there was still a reasonable possibility that the military build-up was primarily intended to extract diplomatic concessions.
Seven weeks later, the uncertainty remains, but the cost of getting the answer wrong has increased considerably.
Russia has continued concentrating military forces around Ukraine. Diplomacy between Moscow, Washington and European governments has intensified without producing an obvious breakthrough. Russia continues demanding security guarantees, including an end to further NATO expansion and restrictions on NATO military activity in Eastern Europe. The United States and its allies reject the idea that Moscow should possess a veto over which countries can join the alliance. Britain has begun supplying Ukraine with anti-tank weapons, and Western governments are discussing severe economic sanctions that could be imposed if Russia attacks.
The strange thing about the current crisis is that almost everyone is making decisions based on an event that has not happened.
Russia has not launched a new invasion of Ukraine.
It may never do so.
Yet troops are moving, weapons are being delivered, diplomats are negotiating, financial markets are evaluating risks and governments are preparing sanctions because policymakers have to respond to the probability of war rather than wait for certainty.
This is what makes deterrence such an unusual political strategy. If it works perfectly, the event it was designed to prevent never occurs. We then have to decide whether the threat was exaggerated or whether the threat disappeared because deterrence worked.
The counterfactual is invisible.
The more immediate problem is credibility. President Biden wants Putin to believe that attacking Ukraine would produce consequences severe enough to make invasion irrational. At the same time, Washington has made clear that Ukraine is not covered by NATO’s collective-defence guarantee and that American forces are not being sent to fight a war against Russia there.
That creates a deliberate limit around Western deterrence.
The United States is essentially telling Russia: we will make an invasion extremely costly, but we are not promising to stop it with American soldiers.
Whether that works depends on what Putin believes those other costs are worth.
Economic sanctions can be extraordinarily powerful. The United States and European Union sit at the centre of global finance, trade and technology. Measures targeting Russian banks, sovereign debt, important companies or access to particular technologies could impose substantial costs on the Russian economy. Germany also possesses leverage through the future of the Nord Stream 2 gas pipeline.
But sanctions have a structural weakness as deterrence.
They punish an action after or as it occurs.
They do not physically prevent Russian tanks from crossing a border.
If Putin believes the geopolitical benefit of military action is greater than the economic cost, sanctions may fail to deter him even if they subsequently damage Russia severely.
This is why saying sanctions will be “unprecedented” tells us less than politicians sometimes imply. The relevant question is not whether Americans or Europeans consider the sanctions enormous. It is how the Kremlin values the trade-off.
Different actors can rationally accept very different costs for the same objective.
For Britain, whether Ukraine eventually joins NATO may be an important security issue.
For Russia, Putin appears to present NATO’s relationship with Ukraine as a fundamental question about the European security order and Russia’s status as a major power.
If Moscow assigns much greater value to the issue than London or Paris does, it may also be willing to absorb much greater costs.
This is one of the asymmetries that makes coercion difficult. The side with more economic power does not automatically possess more bargaining power if the weaker side cares much more intensely about the specific issue being negotiated.
Ukraine obviously cares most intensely of all because the territory and sovereignty at stake are Ukrainian.
That makes the tendency to describe this as a confrontation between Russia and “the West” misleading. Ukraine is not simply the geographical location where two larger blocs happen to disagree. It is an independent state whose citizens have their own preferences about their country’s political orientation.
Russia’s argument is that NATO expansion towards its borders threatens Russian security. That concern should be understood seriously because perceptions of threat influence state behaviour whether outsiders consider those perceptions reasonable or not.
But there is a fundamental contradiction in Moscow’s solution.
Russia says it needs greater security from neighbouring countries.
The methods it has used to obtain that security can make neighbouring countries more frightened of Russia.
Crimea is the clearest example. Russia’s annexation of the peninsula in 2014 may have strengthened its strategic position in the Black Sea, but it also gave Ukrainians an extraordinarily powerful reason to distrust Russian assurances about sovereignty.
The conflict in the Donbas reinforces the same perception.
From Moscow’s perspective, Ukraine moving closer to NATO creates Russian insecurity.
From Kyiv’s perspective, Russian behaviour creates the reason Ukraine wants closer relationships with NATO.
Each side therefore treats the other’s response as proof of its original fear.
This is the security dilemma I discussed in December, but the current crisis demonstrates another feature of it: intentions can change much faster than capabilities.
Russia may genuinely have no intention of attacking NATO today. Eastern European governments still have to plan around Russian military capabilities because they cannot guarantee what Moscow’s intentions will be ten years from now.
Russia makes the same calculation about NATO. Western leaders describe the alliance as defensive. Moscow looks at the military infrastructure and asks what those capabilities could be used for under different political circumstances.
States therefore respond to both intentions and capabilities, but capabilities are often easier to observe.
That makes reassurance difficult.
A politician can promise peaceful intentions.
A tank remains a tank.
The Western response attempts to solve this problem partly by strengthening Ukraine’s capacity to defend itself. Britain has delivered light anti-armour weapons, while the United States and other states have provided various forms of military assistance.
This is deterrence by denial rather than only punishment.
Punishment says: if you attack, we will impose costs afterwards.
Denial says: if you attack, achieving your military objectives will itself become more difficult and expensive.
The distinction is important. A sanction threatens Russia’s economy. An anti-tank weapon threatens the probability that a Russian armoured unit accomplishes its battlefield objective.
Ideally, the two reinforce each other.
But supplying Ukraine with weapons also creates another security-dilemma problem. What the West describes as defensive assistance can be described by Moscow as NATO militarising Ukraine.
Again, the same weapon has different political meanings depending on which side of the border is interpreting it.
That does not mean Britain should refuse to arm Ukraine simply because Russia objects. If threatening a neighbour automatically gave a major power the right to prevent that neighbour strengthening its defences, coercion would reward itself.
It does mean policymakers should understand the feedback mechanism their decisions enter.
Deterrence is not a single move. It is an interaction.
Russia moves forces.
NATO responds.
Russia interprets the response.
NATO interprets Russia’s interpretation.
Each side then updates its behaviour.
A crisis can therefore escalate even when neither side originally wanted war.
This is where communication becomes essential. Diplomacy is sometimes described as the peaceful alternative to deterrence, but that distinction is misleading. Effective deterrence requires diplomacy because threats only work if the other side understands what behaviour triggers them and what path exists for avoiding them.
The United States has therefore been meeting Russian officials while simultaneously threatening sanctions and strengthening Ukraine.
That is not contradictory. The pressure creates incentives to negotiate; the negotiation provides a mechanism through which pressure can be removed.
The harder problem is determining what compromise is actually available.
Russia wants guarantees that NATO will not admit Ukraine and has demanded wider changes to NATO’s military posture in Eastern Europe. The United States and its allies argue that every sovereign country retains the right to choose its own alliances and that Russia cannot dictate NATO policy through military threats.
Both sides have constructed positions tied to principles that are difficult to abandon without appearing to concede something fundamental.
Russia frames the issue as security.
NATO frames it as sovereignty.
Ukraine frames it as national independence.
Once political demands become attached to principles rather than divisible material interests, bargaining becomes harder because compromise can look like betrayal.
You can divide money.
It is much harder to divide a principle.
There may still be areas where agreement is possible. Missile deployments, military exercises, transparency measures and arms-control arrangements can potentially reduce security concerns without formally giving Russia a veto over Ukrainian foreign policy.
Those kinds of agreements may look technical and unambitious compared with the scale of the crisis.
That may be exactly why they are useful.
Diplomacy often succeeds by moving the argument away from questions nobody can compromise on towards specific risks both sides can reduce.
The greatest danger at the moment may be that political leaders become trapped by public commitments. Putin has mobilised enough military power that simply withdrawing it without obtaining anything could be portrayed as a retreat. Western governments have publicly promised severe consequences and insisted that NATO’s basic principles are non-negotiable. Ukraine cannot accept a settlement that makes it appear its future was decided by Moscow and Washington without Ukrainian consent.
Every actor therefore needs an outcome it can describe domestically as something other than defeat.
This is sometimes dismissed as “saving face”, as though it is superficial compared with serious strategic interests.
It isn’t.
Political leaders answer to audiences. Even authoritarian leaders operate within elite coalitions and national narratives. A settlement that humiliates one side can be less stable precisely because the humiliated government has incentives to reverse it later.
Good diplomacy therefore needs off-ramps.
The challenge is creating an off-ramp that allows de-escalation without making escalation profitable.
If Russia receives every major demand after mobilising troops, coercion has succeeded.
If Russia receives nothing at all and withdrawal is framed as humiliation, Moscow may face stronger incentives to escalate rather than retreat.
The bargaining space lies somewhere between those outcomes.
Europe’s role makes the situation even more complicated because “the West” is not one actor. The United States, Britain, Germany, France, Poland and other European countries share an interest in preventing war, but they do not have identical relationships with Russia or identical tolerance for economic costs.
Germany’s dependence on Russian gas makes sanctions involving energy more complicated. Poland and the Baltic states perceive Russian security threats much more directly. France has its own ideas about European strategic autonomy. Britain has adopted a relatively assertive position towards Moscow.
Russia knows these differences exist.
Alliance unity is therefore part of the bargaining process.
If Putin believes sanctions will fracture because European governments cannot tolerate their own economic costs, Western threats become less credible. If European governments demonstrate that they are willing to absorb those costs, deterrence becomes stronger.
Credibility therefore depends partly on the willingness to suffer.
This is true of almost every threat.
A government cannot credibly threaten an action that would be more painful for itself than for the opponent unless the opponent believes it will carry the threat out anyway.
Energy dependence matters because it changes that calculation.
This may explain why economic interdependence produces such ambiguous political effects. Liberal theories of international relations often argue that trade reduces conflict because war becomes more expensive when economies depend on one another.
That is probably true.
But interdependence can also create leverage.
If Europe depends on Russian gas, Russia gains influence over Europe.
If Russia depends on European customers and financial markets, Europe gains influence over Russia.
The same economic relationship that makes conflict costly provides both sides with tools for coercion.
Interdependence does not eliminate power politics.
It changes the instruments through which power operates.
There is also a nuclear shadow over everything happening here. Russia and the United States possess the world’s two largest nuclear arsenals. Nobody seriously wants a direct NATO-Russia war over Ukraine because escalation between nuclear powers carries risks far beyond the territory initially contested.
That is one reason Washington has been explicit about not sending American troops to fight Russia inside Ukraine.
Critics may call that weakness because it tells Moscow where Western deterrence stops.
But ambiguity has costs too. If Russia mistakenly believed NATO would intervene directly, Moscow might make decisions based on a false assumption. Clear limits can reduce miscalculation.
The problem is that clarity can simultaneously weaken deterrence.
If Putin knows what NATO will not do, he can plan around the boundary.
This is the permanent tension between strategic ambiguity and strategic clarity. Ambiguity can deter by making an adversary fear consequences they cannot predict. Clarity can stabilise by reducing the risk of accidental escalation.
There is no universally correct choice.
The appropriate balance depends on the commitment a country is actually willing to defend.
Ukraine is not a NATO member. Pretending otherwise could create a promise Western governments are unwilling to fulfil.
And credibility is damaged not only by making threats that are too weak. It is damaged by making threats that nobody believes you will carry out.
As of tonight, I still do not know whether Putin intends to invade Ukraine.
That sentence feels repetitive after seven weeks, but uncertainty has not become less important simply because the crisis has become more dramatic.
Russia possesses the capability to launch a major military operation. It has concentrated enough forces that Western concern is reasonable. It also continues to deny planning an invasion, and diplomacy is continuing.
The responsible position is therefore neither complacency nor certainty.
It is preparation.
Western governments should make the economic and military costs of aggression clear enough that Moscow understands them before making a decision. They should strengthen Ukraine’s ability to impose costs on an attacker. They should continue negotiating seriously over arms control and reciprocal security measures that do not surrender Ukraine’s sovereignty. And they should avoid rhetoric that makes compromise politically impossible.
None of those policies guarantees peace.
Deterrence does not produce guarantees.
It changes probabilities.
That may be one of the most important things I have learned from following politics over the last year. Governments rarely choose between certainty and uncertainty. They choose between different distributions of risk.
Arming Ukraine risks escalating Russian threat perceptions but may reduce the probability of invasion.
Refusing to arm Ukraine may reduce immediate tensions but make military action appear cheaper.
Sanctions threaten Russia but impose costs on Europe too.
Diplomatic concessions may reduce tensions but encourage future coercion.
Refusing concessions protects principles but can narrow the bargaining space.
Every policy moves several variables simultaneously.
The task is not finding the option without risk.
It is deciding which risks are worth accepting to reduce the ones that matter most.
For Ukraine, the largest risk is obvious: war on its territory.
For Russia, the stated risk is an increasingly Western-aligned Ukraine integrated into NATO’s security system.
For NATO, the risk is allowing military coercion to rewrite the European security order.
The crisis can end peacefully only if diplomacy constructs an outcome in which all three conclude that restraint is less costly than escalation.
That may be possible.
It may not.
But the next several weeks will test whether deterrence is working in the only way successful deterrence can ever really be tested:
by whether something does not happen.
