The world's longest-lasting military alliances

Despite facing growing internal strains and new external challenges, the NATO alliance has successfully prevented conflict in Europe since its creation in the aftermath of World War II. It's also celebrating its 7oth anniversary this month.

Reproduced from GZERO Media chart via Brookings; Chart: Axios Visuals

Consider this: In the past three centuries, only one similar collective defense agreement has lasted longer, according to a Brookings Institution study. The chart above puts NATO's longevity into historical context.

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NATO at 70: Checking up on the alliance's health

Portuguese troops mark the 70th anniversary of NATO's founding. Photo: Horacio Villalobos/Corbis via Getty Images

Washington has this week been toasting NATO, which turns 70 today. Congress greeted NATO Secretary-General Jens Stoltenberg with bursts of bipartisan applause, and foreign ministers from the 29 member countries gathered today to reaffirm their mutual support.

The big picture: As former Supreme Allied Commander James Stavridis writes in TIME: “Perhaps NATO’s greatest accomplishment is not even its unblemished record of deterring attack against its members but rather the fact that no alliance nation has ever attacked another.”