Use of NATO arms for attack in Russia raises doubts about Kyiv’s controls

The Russian fighters aligned against Moscow who launched a cross-border raid from Ukraine into the Belgorod region of Russia last week used at least four tactical vehicles originally given to Ukraine by the United States and Poland, U.S. officials said, raising questions about the unintended use of NATO-provided equipment and Kyiv’s commitments to secure materiel supplied by its supporters.

Three of the Mine-Resistant Ambush Protected vehicles, also known as MRAPs, taken into Russia by the fighters were provided by the United States and the fourth was from Poland, according to people familiar with...