Key Takeaways From America’s Secret Military Partnership With Ukraine

The war in Ukraine is at an inflection point, with President Trump seeking rapprochement with the Russian leader, Vladimir V. Putin, and pressing for an end to the fighting.

But for nearly three years before Mr. Trump’s return to power, the United States and Ukraine were joined in an extraordinary partnership of intelligence, strategy, planning and technology whose evolution and inner workings have been known only to a small circle of American and allied officials.