Bangladesh, Aug. 22 -- If the objective of diplomacy is to end a conflict, there is little strategic logic in refusing to engage the principal political actors involved. Even when those actors are deeply controversial, direct communication can be essential to negotiating ceasefires, exchanging commitments and eventually reaching a political settlement.

That is why Jared Kushners meeting in Cairo with Khalil Hayya, the newly elected leader of Hamas, can be understood as pragmatic diplomacy. Hamas remains a significant actor in the Gaza conflict, and any serious effort to achieve a lasting settlement may require communication with its leadership.

But diplomacy becomes difficult to defend when engagement with one Palestinian faction is acc...