Finland becomes the 31st member of NATO on Tuesday, in a historic strategic shift provoked by Moscow's war on Ukraine, which doubles the US-led alliance's border with Russia. Last year, the Kremlin's all-out invasion of Ukraine upended Europe's security landscape and prompted Finland -- and its neighbor Sweden -- to drop decades of military non-alignment. Awkward allies Turkey and Hungary, for different reasons of their own, delayed Finland's bid to come under the NATO umbrella -- and Stockholm's progress remains blocked. But last week, the Turkish parliament voted to clear Finland's final hurdle. Completing the ratification in well under a...