Middle East diplomacy regularly inspires such extremist violence. Sadly, it has become predictable precisely because it has frequently succeeded in disrupting or derailing negotiations. Israeli Prime Minister Binyamin Netanyahu wisely went ahead with the Washington talks in spite of the first attack, which killed two men and two women, one of whom was pregnant. But the incidents cast a substantial shadow over the talks, for two reasons.
One was Hamas’s overt assertion of responsibility — something it has often avoided in recent years. A spokesman for the movement’s armed wing claimed the attacks were just the beginning of a series; in Gaza, Hamas’s supporters held a demonstration to celebrate the murders. Those who supposed that the Islamic movement would quietly observe and even passively support the bargaining of Palestinian President Mahmoud Abbas with Mr. Netanyahu were brutally corrected. Second, violence by Hamas in the West Bank serves to underscore one of the central Israeli concerns about a peace settlement: that under Palestinian rule the West Bank could become another base for attacks on Israel, as Gaza is.
Israel may be able to partly deter Hamas with the threat of counterstrikes or another invasion of Gaza. But the only real counter to attacks such as those of last week is effective policing by Mr. Abbas’s U.S.-mentored security forces. Palestinian police duly rounded up scores of Hamas operatives last week but quickly released them — reminding some of former Palestinian leader Yasser Arafat’s duplicitous response to acts of terrorism.
Mr. Abbas has been convincing in his renunciation of violence and in his opposition to Hamas. He has promised repeatedly to fight terrorism. But if the talks are to succeed, it is essential that he match intentions with actions.