Russia and Ukraine began a major prisoner exchange Friday, swapping hundreds of soldiers and civilians in the first phase of an exchange that was a moment of cooperation in otherwise failed efforts to reach a ceasefire in the 3-year-old war.

Russia and Ukraine were set to take part in a major prisoner swap on Friday, described as the biggest since the start of the full-scale Russian invasion in 2022.

Ukraine’s capital came under a large-scale combined drone and missile attack late Friday with explosions and machine gun fire heard throughout the city. Many Kyiv residents were taking shelter in underground subway stations.

Tragically, if he doesn’t, his most important foreign policy initiative will probably collapse — with violent aftershocks that could plague his entire term.