Russia is readying a massive, new offensive in eastern Ukraine, hoping to reverse its fortunes on the battlefield after a catastrophic start to seven weeks of war. A long convoy of combat vehicles has jammed highways across northeastern Ukraine in preparation for an attack that could begin within days, and the Kremlin has named a general known for overseeing Moscow’s campaign in Syria to lead it. A failed Russian attempt to storm Kyiv and other big cities took a heavy toll in personnel and equipment, boosted morale in Ukraine and allowed it to rally broad international support. Russian President Vladimir Putin badly needs a quick battlefield victory to find an exit from what increasingly looks like a catastrophic quagmire.