Fallout from U.S. cluster munitions decision strains NATO unity over Ukraine

NATO leaders gathered in Lithuania's capital on Tuesday after spending the days running up to their annual summit bulldozing some of the most contentious and divisive issues — including defence spending and Sweden's proposed membership in the military alliance — off the agenda.

However, concern about the decision by the United States to provide cluster munitions to Ukraine is a fresh challenge to allied unity.

Keeping everyone on the same page was a preoccupation of Prime Minister Justin Trudeau in his remarks going into the gathering in Vilnius.

"This NATO Summit is going to be an opportunity for all of us to gather to demonstrate our solidarity and our conviction that continuing to step up and stand together is the path to a more peaceful world," Trudeau said Monday while announcing an increased Canadian military commitment in eastern Europe.

As he spoke, the leaders of Turkey and Sweden hammered out their differences over the stalled admission of the Nordic country. Ankara, on the eve of the meeting, dropped its opposition, clearing the path for Stockholm's eventual inclusion as NATO's 32nd member. 

"This summit is already historic before it has started," Jens Stoltenberg, the secretary general of the alliance, said early Tuesday.

Watch: NATO boss asked about lack of timeline for Ukraine membership:

Turkey's year-long refusal to give its consent for Sweden's application has been a major irritant and drag on allied unity. The deal, brokered late Monday, is a boost to the alliance. 

In formally greeting U.S. President Joe Biden on Tuesday, Stoltenberg also touted how countries have agreed on a new defence funding formula that will see the minimum level set at two percent of a nation's gross domestic product.

Biden was asked last week why the U.S. plans to deliver cluster munitions to Ukraine — munitions that can be dropped from the air or fired from howitzers, spreading small bomblets over a large area.

"They've run out of ammunition," the U.S. president said, referring to the shortage of large-calibre artillery shells in both Ukraine and among allied nations supplying them.

Cluster munitions are banned under international law, in a treaty ratified almost 13 years ago. As of February 2022, when Russia invaded Ukraine, a total of 123 states, including Canada, had joined the convention. 

Among the nations who are not signatories: the United States, Russia and Ukraine.

The U.S. decision to supply the munitions, which are widely seen as indiscriminately killing and wounding civilians, presents a new, urgent dilemma for allies who are trying to remain united behind Ukraine.