Ukraine

The guided-missile destroyer Donald Cook's passage into the Black Sea was denounced by Moscow.

Defense Secretary Hagel called on NATO allies to boost defense spending to prepare for the threat of an expansionist Russia.

The U.S. will support an expanded and more agile rapid reaction force within NATO to counter the growing threat from Russia...

Thirteen months after Russia began its occupation of Crimea, the United States and its European allies must remain steadfast.

The U.S. and its NATO allies have trained with the Ukraine military and pumped millions of dollars into that country's...

The Russian buildup of military forces threatening Ukraine was real and Moscow’s denials were baseless, NATO officials said.

Western allies bolstered Eastern Europe defenses as Ukraine pressed an offensive against pro-Russian militants.

Troops from the 173rd Airborne Brigade will join in allied military exercises in Ukraine next week.

Army Gen. Curtis M. "Mike" Scaparrotti toured the combat positions of Ukrainian troops facing off against Russian troops.