Fred Tanner Friends and weapons: the architecture of security guarantees for Ukraine »There are no security guarantees except friends and wea­pons.« 1 President Zelensky‘s sober assessment at the UN General Assembly in September 2025 reflects current per ­ceptions of the role and usefulness of security guarantees. Security commitments under the term»security guaran­tees« have become rather ambiguous in high-stakes inter­national security policies. Security guarantees typically come in one of two forms: binding alliance commitments – most notably NATO membership – or formal pledges by militarily superior states to defend weaker nations, someti­mes reinforced by robust peacekeeping or enforcement operations. Effective guarantees require both legal obligati­ons and credible military backing, as demonstrated by NA­TO‘s Article 5 collective defence provision. Ukraine‘s cur ­rent situation, however, satisfies neither criterion. But secu­rity guarantees are still in demand. In the event of termination of the conflict between Russia and Ukraine, a key challenge would be how to ensure that the ceasefire is not exploited by either side to rearm for renewed acts of war. The prospects of a peaceful settlement in Ukraine are limi­ted. Apart from the brief Istanbul talks in March–April 2022, there were only limited signs of progress until early 2025, when the Trump administration opened communica ­tion channels with Russia. Since the outset of Russia’s in­vasion, Ukraine has sought credible defence commitments, recognising that opposition within NATO would block its accession and, with that, the protection under Article 5. For such commitments to be meaningful and credible, they must demonstrate the guarantor’s military capability, wil­lingness and alignment of interests. 2 From a Western per­spective, security guarantees are intended to reassure Kyiv and deter Moscow, albeit without committing them to go to war for Ukraine. While protection could be formalised for a post-war setting, certain forms of support, such as mi­litary aid, training and security assistance, have already been and continue to be provided by Western countries since Russia‘s invasion in 2022. 1 President Zelensky, statement UNGA, 24.09.25. 2 Lawrence Freedman(2025): Can the West guarantee Ukraine’s security?, in: The New Statesman, 31 January. Friends and weapons: the architecture of security guarantees for Ukraine 1