A ceasefire between the Ukrainian government and pro-Russian rebels appears to be holding despite a weekend of scattered attacks. A deal brokered on Friday was followed by clashes around 24 hours later in Donetsk and Mariupol. The truce lays out the “decentralization of power” as a key component of any long-term agreement, but both Ukraine and its rival Russia have pushed diverging proposals for what that would mean. It also calls for a mass prisoner exchange. The ceasefire was reached as NATO approved a 4,000-strong force capable of rapid deployment in eastern Europe to confront Russia.