An EU-brokered normalization deal between Kosovo and Serbia marks a key first step in resolving a simmering conflict that has threatened to return the Balkans to war. But significant constraints remain toward a legally binding comprehensive agreement. Serbian President Aleksandar Vucic and Kosovar Prime Minister Albin Kurti agreed on Feb. 27 to an EU-sponsored deal to normalize the relations between the two Balkan neighbors during a meeting in Brussels. Under the 11-point plan, Serbia and Kosovo are required to ''develop normal, good-neighborly relations with each other on the basis of equal rights.'' Neither party has to formally recognize the other as a state, but both have to respect the territorial integrity of the other, refrain from any action that would renew tensions on the ground and exchange permanent missions in each other's capitals. While Serbia does not have to formally recognize Kosovo as an independent state, it will recognize Kosovo's...