Once rock-solid, the support that Ukraine has gotten from its biggest backers for its fight against Russia is showing cracks. Political posturing in places like Poland and Slovakia, where a trade dispute with Ukraine has stirred tensions, and Republican reticence in the United States about Washington’s big spending to prop up Ukraine’s military have raised new uncertainties about the West’s commitment to its efforts to expel Russian invaders more than 18 months into the war.

And Russian President Vladimir Putin, who hopes to outlast allied backing for Kyiv, will be ready to capitalise if he sees Ukraine is running low on air defence or other weapons. The West has long been shoulder-to-shoulder with Ukraine against Russia. But between Ukraine’s impassioned, unending pleas for help, and huge handouts from its backers, signs of discord have emerged. In July, Britain’s defence minister at the time said Ukraine should show “gratitude” to the West, after Kyiv renewed its vocal “but unsuccessful” push to join NATO.