Ukraine and expansion top NATO agenda as Biden tries to cement unity

WASHINGTON — President Joe Biden and fellow leaders of NATO will come together next week extolling their remarkable unity backing Ukraine in its war with Russia. But serious differences over expansion of the transatlantic alliance threaten to disrupt the harmony and turn the annual summit on its head.

Cohesion among the North Atlantic Treaty Organization’s members has also been jeopardized by the war having become a seemingly interminable slog. Even Ukrainian President, Volodymyr Zelenskyy has said a long-anticipated counteroffensive against Russian invaders is not going as well as he hoped.

NATO’s gathering in the Lithuanian capital of Vilnius will focus world leaders on how to help nonmember Ukraine, including what kind of military aid to provide and what a longer-term security arrangement should look like — whether or not it includes future membership in the alliance. The summit comes in the wake of an