This time, the two countries’ militaries will be operating on open terrain well-suited for massed forces and armored thrusts. Russian forces will also be fighting in closer proximity to their bases in western Russia, giving them shorter supply lines, and on territory their commanders know better…

“You could almost say it’s a whole new war now,” said retired Lt. Gen. Ben Hodges, a former commander of the U.S. Army in Europe, who predicts “a classic steel-on-steel, heavy firepower offensive” fight…

Both sides are preparing for tougher combat ahead. To bolster Ukraine’s forces, the U.S. has expanded intelligence sharing with Kyiv to include targets in Russian-occupied Donbas and Crimea. For the first time, the U.S. is also sending 155 mm howitzers as part of a fresh infusion of weapons.

Ukrainian forces, however, are confronting a Russian military that has more long-range artillery and armored punch, despite the losses Moscow has suffered during the war. The Ukrainians are also operating at the end of supply lines that stretch back to the country’s western border, where weapons are arriving via Poland, Romania and other neighboring allies.