As the investigation into Wednesday's twin suicide bombings in Jerusalem closed in on the West Bank village of Dahariya, and two 21-year-olds who disappeared from their homes there several months ago, Palestinian police officials breathed a public sigh of relief.
Since it appeared that the bombers responsible for the carnage in the Jerusalem vegetable market had come from an area outside the major West Bank cities, an area still under Israeli security control, senior Palestinian police officers asserted in interviews, Israel could hardly blame the Palestinian Authority for failing to thwart the attack.
In the three bomb-strewn years between 1993 and 1996, when Mr Yitzhak Rabin and Mr Shimon Peres were leading Israel, that kind of argument was sympathetically received in government circles.
The Labour-led governments which sought a partnership with Mr Yasser Arafat's Palestinian Authority, recognised that militants on both sides would try to derail their peace efforts, and believed that the end goal of co-existence was worth pursuing even through the bombings.
There was also a sense that issuing relentless demands to Mr Arafat to wage all- out war on Hamas - which enjoys the support of perhaps a quarter of the Palestinian population - might lead to a fiery confrontation within the Palestinian areas, and might even prompt Mr Arafat's demise.
But Mr Benjamin Netanyahu came to power in Israel last year offering a very different approach - promising that Israelis' everyday security needs would take precedence over all other issues, and that if Mr Arafat could not ensure that the bombers among his own people were kept quiet, Israel would do the job for him.
Faced with the first major test of that tougher approach in the wake of Wednesday's bombing, aides to Mr Netanyahu were yesterday thoroughly disinclined to let Mr Arafat off the hook merely because it appeared that the bombers had not grown up in an area under full Palestinian Authority control.
Less than 24 hours after they had demanded that Mr Arafat change his strategy and tackle the Hamas militants head-to-head, Israeli officials were already expressing displeasure at what they said was apparent inaction.
"The Palestinians are definitely making an effort to investigate the bombings," said one Israeli official, "but we see no signs yet of a genuine, stepped-up battle against the Hamas infrastructure."
Mr Arafat appears in the past to have steered a middle path - keeping Hamas quiet enough to mollify the Israelis, without risking all-out confrontation with the extremists.
His regime has lost popular support over the months because of the peace deadlock, and more recently because of grave corruption allegations against many of his ministers.
By now suspending peace talks altogether, blockading West Bank cities, urging donor nations to halt his funding, and preparing to jam his radio and TV stations, the Netanyahu government knows it is weakening Mr Arafat's rule still further.
And the intention, apparently, is to force Mr Arafat's hand - to force the Palestinian president, once and for all, to choose between Hamas and Israel as his partner. David Horovitz is managing editor of the Jerusalem Report