**U.S. security guarantees for Ukraine remain tied to a broader peace settlement with Russia, which has not been reached despite months of talks involving Trump administration envoys.** Negotiations in 2026 produced draft commitments and statements of support from the U.S. and European partners, yet any formal bilateral agreement requires Ukrainian acceptance of territorial compromises—particularly on Donbas—that Kyiv has rejected, followed by U.S. Congressional ratification. Recent developments, including an announced energy ceasefire, pressure over refinery strikes, and a diesel import arrangement with Moscow, have heightened tensions without advancing a finalized guarantee. With roughly 2.5 months until the December 31 deadline and persistent gaps on core issues, traders assign overwhelming probability to no agreement materializing. Late breakthroughs in trilateral diplomacy or rapid congressional action could still shift the outcome before year-end.