The instability of Europe, a more-assertive China and the prospect of another Donald Trump presidency are lending special importance to this year’s annual summit of NATO leaders in Washington. The military alliance — which considers an attack on one of its members as an attack on all — is celebrating its 75th anniversary this month. But as David Akin tells us, the growing gap between Western powers, including Canada, and those on the Eastern flank is creating a lot of anxiety about the future of the alliance.