Ukraine national guard soldiers BTR-4E armored personnel carrier
Ukrainian National Guard members train on a BTR-4E armored personnel carrier in the Kharkiv region on April 21.
  • Ukraine's military is gearing up for offensives against Russian forces in spring and summer.
  • Ukraine has taken heavy casualties, but its military has grown due to recruitment and mobilization.
  • As a result, Ukraine now fields a force with a mix of experienced soldiers and new recruits.

Following Russia's illegal annexation of Crimea and the start of the war in the Donbas in 2014, the US and other NATO militaries began training the Ukrainian military to prepare it for a large-scale conflict.