Amid ever-escalating aerial assaults, accelerating Russian advances in the east, and the weariness that comes with nearly 3.5 years of war, all eyes in Ukraine are once again focused upon one man — U.

In the north a 50,000-strong Russian force is attacking Sumy, a provincial capital. Our model is detecting artillery fire and explosions along the city’s northern defensive lines. Ukraine is badly outnumbered but officials say the front is holding.

KYIV, Ukraine -- An emboldened Russia has ramped up military offensives on two fronts in Ukraine, scattering Kyiv’s precious reserve troops and threatening to expand the fighting to a new Ukrainian region as each side seeks an advantage before the fighting season wanes in the autumn.