President Volodymyr Zelensky is caught in a bind.

Ukraine's long-awaited counteroffensive has—so far—proved underwhelming, his troops winning back slivers of land in the south and east of the country at high cost. The Ukrainians are reportedly inflicting withering losses on the Russian defenders, but six weeks into the operation, Moscow's multi-layered defensive network is yet to break.

Zelensky faces an impossible choice: to go all-in and risk a costly failure, or to cut Ukraine's losses and accept a politically damaging defeat.