As fighting erupted throughout eastern Ukraine on Friday before a cease-fire begins on Saturday night, the United States accused Russia of joining separatist rebels in an all-out attack on Ukrainian forces around the contested town of Debaltseve. When the pact was signed with a two-day window before the truce, some last-minute jockeying for position was expected. But the intensity and scope of the violence raised concerns that the agreement signed this week, rife with ill-defined and ambiguous provisions, might prove as ineffective as the first cease-fire pact, signed in September. Artillery shelling and gunfire reverberated in the area […]