Russian Nukes in Belarus: Why Putin Is Escalating Again

Russian President Vladimir Putin is again reverting to his most effective card as his troops struggle to make significant headway on the devastated frontlines of Ukraine and as Kyiv prepares to turn its new Western weapons against Moscow's occupying forces.

The Russian president announced this weekend that Moscow would build storage facilities for tactical nuclear weapons—which are designed with a smaller yield and intended for battlefield rather than strategic use—in Belarus and train Belarusian pilots to deliver the warheads from their own Su-24 aircraft.

Putin gave no indication of when...