The US Army has suddenly removed the general in charge of the corps that helps coordinate American support to Ukraine. The Army abruptly fired Lieutenant General Charles Costanza, commander of V Corps, roughly two months before his scheduled departure, ABC News reports.

The corps he led is central to the US role on NATO's front line with Russia. Costanza had commanded V Corps since April 2024, a corps partly based in Poland that has taken on an increasingly prominent role since Russia's full-scale war against Ukraine, helping coordinate US military support for Ukraine and managing the American presence on NATO's eastern flank.

The reason has not been made public

The Army confirmed the removal but not its cause. A service spokesperson said the circumstances remained unclear, and the Army said the matter was "referred to the appropriate authority in accordance with Army regulations," according to The Hill.

Reporting points away from politics. Two US officials told journalists that the removal was not political and was not initiated by Defense Secretary Pete Hegseth, with one source citing conduct that could ground a commander's removal at any level and a former defense official citing alcohol problems. Brigadier General John Mountford, the deputy commander for readiness, has begun his service as acting commander.

It comes amid a wider shake-up of the top brass

The timing places it in a turbulent period for US military leadership. Costanza's removal comes amid a broader shake-up in which more than two dozen senior officers have been removed or sidelined under Hegseth, often without public explanation.

The backdrop is US force posture in Poland

The command change lands amid questions over the US presence in Poland. This year, the Pentagon canceled a planned deployment of a Fort Hood-based armored brigade to Poland, and after the cancellation drew criticism in Warsaw, President Donald Trump announced the US would deploy 5,000 troops in the country.