On April 4, 2019, the North Atlantic Treaty Organization will celebrate its 70thanniversary. Since its founding with twelve members in 1949 NATO has been enlarged in several stages to now include twenty-seven European countries, the United States, and Canada. Four countries — Bosnia and Herzegovina, Georgia, Macedonia, and Ukraine — are officially designated as aspiring members, and an additional 21 countries participate in NATO’s Partnership for Peace program.

The Alliance has recently reinforced its presence in Eastern Europe to counter aggressive Russian behavior. Members have committed to reach or maintain defense spending of at least 2% of GDP by 2024. Reaching that goal, and how the outlays should best be spent, remain high on the NATO agenda; as does the performance of alliance command structures.