On Monday Russia’s defence ministry said it had signed a contract to bring the Akhmat group of Chechen special forces under its control. It follows an order that all “volunteer” units should sign similar agreements by 1 July so they ultimately answer to Sergei Shoigu, the Russian defence minister; in exchange, volunteer fighters get benefits including support for their families if they are wounded or killed. The agreement with the Akhmat group matters more because of who won’t play ball: Yevgeny Prigozhin, the head of the Wagner mercenary group, has refused to sign. Prigozhin has been escalating a long-running feud with the defence ministry – he said on Sunday that Shoigu “cannot properly manage military formations”. His endgame is unclear – beyond amassing more power for himself.