“I am happy to be here today and to see you,” Ukrainian President Volodymyr Zelensky said as he presented medals to troops near the city of Kupiansk, close to the front line in the war-battered Kharkiv region on Monday. But the view from the battlefield is far from happy for Ukraine. The army’s former momentum has stalled. Zelensky recently replaced much of the military leadership in the most significant shake-up since the war began. He sacked popular army chief Valerii Zaluzhnyi, credited with the army’s stunning success in holding out against vastly more powerful Russian forces at the onset …