Stephen Booth is Head of the Britain in the World Project at Policy Exchange.

Vladimir Putin’s threats to invade and further destabilise Ukraine appear to be reaching crisis point. No one yet knows how this will play out. Putin has waged a long-standing campaign to subordinate Ukraine to Russian influence. He has seemingly also sensed an opportune moment to test transatlantic unity in upholding wider European security and NATO’s eastern flank.

Brexit catastrophists believed that the UK would be consigned to geopolitical irrelevance outside the EU. Therefore, it is significant that the UK’s response under the leadership of the Prime Minister has been more forward-leaning than many NATO allies. It is other nations, such as Germany, which have been criticised for pursuing a narrower national interest. For all the talk of Russian money in London, it is the UK that has taken the most hawkish stance of the major European players.

In recent days, western powers have been trying to coalesce around a package of economic and financial sanctions in response to various actions Russian forces may take. However, as James Sherr, a leading Russia expert, told the House of Commons Defence Select Committee this week, Putin has staked a great deal of his personal reputation on taking the aggressive stance that he has. “You cannot deter Russia by economic and financial means alone,” he warned. Showing resolve on security is just as important.

Putin will weigh the combined economic, security, and reputational consequences of any course of action. It may be impossible to prevent a Russian incursion into Ukraine, but if the consequences of such action are clearly and credibly negative for his wider strategic interests, Putin might yet be deterred. “It’s not enough to talk deterrence,” Sherr noted. “You have to do deterrence.”

Moves by the US, UK, and some other NATO allies to supply weapons and technical assistance to Ukraine are a clear signal that they intend to ensure that military action in Ukraine will be painful and difficult for Russia.

It is significant that the US has put 8,500 personnel on heightened alert to potentially deploy to NATO members in Eastern Europe. Boris Johnson this week said the UK would contribute to any new deployments, and a number of other NATO allies have made announcements that they will send jets and warships to the region. If Russian aggression is met with a renewed NATO focus on its capabilities and security in Eastern Europe, it would surely be counterproductive from Putin’s point of view, or at least put doubt in his mind.

Meanwhile, the European response has revealed deep-seated differences in attitudes to Russia and internal suspicions of individual governments’ motivations.

There have been clear divisions over the question of supplying weapons to Ukraine. And, while EU governments are united behind the principle of providing economic aid and imposing sanctions, there has been much debate about what form they should take, including whether cyber-attacks or a “false-flag” operation should meet the threshold for sanctions, or whether these should only be triggered in the event of a full invasion. Washington has been trying to convince Brussels of the need for the most economically punishing measures.

Russia is keen to exploit this division. Yesterday, several top Italian business executives went ahead with a conference call with Putin on investment prospects in Russia, ignoring an appeal from their own government to cancel the event.

A long-time proponent of thawing relations with Moscow, Emmanuel Macron’s messaging has been erratic. In a speech to the European Parliament last week to mark France’s EU Presidency, he called on the EU to come up with its own proposal for a “new security and stability order” and “then share it with our allies in the NATO framework.” His vision for French leadership of a strategically autonomous EU foreign policy is a recurrent theme of his leadership as he faces a Presidential election in the spring.

French and EU officials sought to reassure Washington that Macron’s remarks were not in opposition to the continuing US negotiations but designed to strengthen rather than undermine NATO unity. Indeed, in recent days, France has expressed its readiness to send troops to Romania under NATO command. However, having previously described the “brain death” of NATO, Macron should not be surprised his remarks caused confusion in Washington and other European capitals.

Germany’s position has come under the most criticism. Berlin’s refusal to join other NATO members in providing weapons to Ukraine and its hesitancy over halting the Nord Stream 2 gas pipeline highlight the deep institutional reluctance to confront Russia, due to historical and commercial reasons. Wolfgang Ischinger, Germany’s former ambassador to the UK, US, and now head of the annual Munich Security Conference, asked this week “How many in Berlin are actually aware how our seemingly confused Ukraine policy harms not just (Germany) but the entire EU?”

Ultimately, this crisis has underlined that, on the question of the biggest traditional security threat to Europe, the UK remains the most important European player and NATO is the only game in town. It is significant that the crisis has revived the debate around NATO membership in Sweden and Finland.

It is also evident that security cooperation could provide a basis for stronger political relationships with certain EU member states – the Nordics and Eastern members in particular – in the future. Many of these countries are wary of a Franco-German rapprochement with Russia at their expense and are certainly open to alternative sources of reassurance.

This reassurance has naturally predominantly come from the US. Equally, the crisis has demonstrated – as did the recent AUKUS security pact – the UK’s continued geopolitical relevance to Washington and the transatlantic alliance. As Sherr, who did not support Brexit, told the Defence Select Committee, “We’ve revived our reputation of being a country that punches above its weight.”

Critics of the UK’s “Indo-Pacific tilt” suggested it would lead to Britain taking its eye off the ball in Europe. Ensuring our capabilities remain well-resourced is clearly a significant challenge, but the current crisis illustrates that Global Britain can be present both in Europe and further afield.