This week the U.K. announced it would be the first country to send Ukraine modern Western main battle tanks. The number of Challenger 2s heading to Ukraine is small – a company of 14 tanks – but the strategic effect of this decision could be very large if it achieves the UK’s aim of “unlocking” the “Leopard coalition” of European countries who own over 2000 Leopard tanks but need Germany’s approval to send them to Ukraine.

UK ministers have been on a mission this week to get results. Foreign Secretary James Cleverly was in Washington D.C. before Defense Secretary Ben Wallace went to Estonia where he announced ‘The Tallinn Pledge’, alongside Estonia, Poland, Latvia, Lithuania, Denmark, the Czech Republic, the Netherlands, and Slovakia.

The pledge unveiled a massive amount of new military assistance for Ukraine to go with the UK’s Challenger II tanks. It was also designed to put more pressure on Germany to approve the Leopard II transfers to Ukraine, confirming Poland’s desire to send Leopard IIs, pending which “a wider coalition of Leopard 2 tanks donors will be established”.

All eyes will be on the U.S.-led Ukraine Defense Contact Group in Ramstein, Germany, tomorrow to see if these efforts bear fruit.

The Tallin Pledge and Challenger II transfers are the latest in a concerted UK strategy to get the most out of its resources and turn the “Global Britain” rhetoric into reality.

While this approach has been expedited since Brexit to demonstrate leadership outside of the EU, it is also rooted in the UK’s instinct to be at the center of world events. However, this strategy comes with important risks London must manage in the coming months.

The UK’s approach is most evident in Ukraine. Through 2022 the UK provided more aid to Ukraine ($2.85 billion) than any other nation except the United States and has committed to the same level in 2023. The UK was also the first to provide Next Generation Light Antitank Weapons, known as NLAW and made in Northern Ireland, rushed to Ukraine in large enough numbers to help turn the tide early in the war. The opening up of UK intelligence has played a key role in shaping public awareness of events on the ground. Building on its experience training Ukrainian soldiers since 2015, the UK spearheaded Operation Interflex in June to train over 10,000 on British soil alongside several international partners.

The Tallin Pledge also underscores this approach in Northern Europe. In May, then-Prime Minister Boris Johnson traveled to Sweden and Finland to sign written security assurances which helped pave the way for their NATO membership bids. Both nations are also part of the UK-led Joint Expeditionary Force (JEF), which deployed forces and its headquarters to the Baltic region and held a leaders’ summit with President Zelenskyy. It is JEF nations who will contribute to a new Danish/UK International Fund for Ukraine and who form the backbone of Operation Interflex and the Tallin Pledge.

Despite self-destructing in the top job of prime minister, as foreign secretary Liz Truss laid out the principles behind this strategy in a speech two months before the war with the grandiose title of “Building the Network of Liberty.” The big idea was to use Britain’s soft power to build “a network of security partnerships to protect our people, our partners and our freedoms”, with “Global Britain” as the hub.

Although that aspirational term has disappeared from the government’s lexicon, the idea remains. In his first foreign policy speech, Truss’ successor Rishi Sunak committed to “dramatically increasing the quality and depth of our partnerships with like-minded allies around the world.” He cited AUKUS (with the United States and Australia), the Five Power Defence Arrangements (with Australia, Malaysia, New Zealand and Singapore) and the Future Combat Air System (with Italy and Japan) as global examples.

However, this strategy comes with three important risks London needs to actively manage.

The first is to allied unity. The flipside of getting out ahead of others – most notably Berlin and Washington on providing main battle tanks to Ukraine – to demonstrate leadership is revealing divisions among Western allies which could be exploited by Russia and others. Western support for Ukraine is strongest when it is united: London should be careful not to undermine this. The US-led Ukraine Defense Contact group should remain the primary forum for agreeing and announcing further support.

The second is over-extending. The British Army chief has already warned providing Challenger IIs to Ukraine will leave his force “temporarily weaker.” The consequences of the extraordinary amount of munitions sent to Ukraine may take “decades” to address. As the U.S. can attest, global leadership comes with a price tag. Sunak has since backed off Truss’ short-lived target to spend 3% of GDP on defense, while increasing support to Ukraine and doing more “both at home in our European neighborhood and in the Indo-Pacific.” This circle must be squared in his government’s ongoing refresh of the 2021 Integrated Review (IR) of defense and security.

The third is the appearance of a zero-sum approach to European security – particularly vis-à-vis the EU. Despite pragmatic cooperation on Ukraine, including joining the EU’s military mobility project, the UK’s post-Brexit policy of shunning formal cooperation with the EU on defense and security still risks fratricide. There is also a risk the JEF is seen as competing with NATO, rather than being complementary. This must be clarified with key partners – especially given the JEF’s origins in NATO. The IR refresh provides an opportunity to reset the UK’s approach to European security.

These risks are real and must be carefully managed in the coming months. But as the sound of Ukrainian soldiers reportedly yelling “God save the Queen!” when firing NLAW missiles attests, Britain’s friends appreciate its leadership.

Sean Monaghan is a visiting fellow in the Europe, Russia, and Eurasia Program at the Center for Strategic and International Studies, where he focuses on NATO, European security, and defense. A career civil servant with the U.K. Ministry of Defence, he most recently served as a defense policy analyst.

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