Ukraine’s war prospects have grown notably bleaker in recent weeks, with Kyiv overwhelmed by Russian air power and facing an acute cash crunch, a swirl of corruption allegations, new internal political divisions and growing exhaustion among its international supporters — even as the Trump administration is now pushing to revive long-stalled peace negotiations. Amid the constant Russian drone and missile attacks, two shortfalls are raising the greatest alarm: a lack of air defense interceptors and an unexpected $27 billion budget gap that Ukrainian officials say must be filled by year’s end. President Donald Trump on Sunday added new pressure, urging...