<h1>European and NATO leaders back Ukraine's push for Article 5-like security guarantees, long-term military aid, and legal questions</h1> European and NATO leaders will accompany the Ukrainian president to Washington to press the U.S. president for durable, Article 5-like security guarantees and long-term military training, equipment and financing as part of negotiations to end the war with Russia. The Russian president reportedly signaled tentative agreement to such guarantees at a bilateral summit with the U.S. president, altering bargaining positions. European proposals include a multilateral 'coalition of the willing' presence in Ukraine away from front lines to reassure Kyiv, raising legal issues about sovereignty, use-of-force thresholds, treaty-like security commitments versus informal guarantees, and potential conflicts from disparate allied messages on ceasefire versus final peace terms.