Quotes of the Day

The package bomb that exploded at a busy Jerusalem bus stop on Wednesday, killing a 60-year-old British woman and wounding 39, was exceptional in more ways than one. The holy city hasn't had a terrorist attack since 2008, so the homemade explosive sent a charge through a sprawling metropolis that, in a matter of minutes, became clogged with impromptu checkpoints, with rush-hour traffic funneling into single lanes to pass through them.

And the nature of the strike was exceptional. Police say only about four pounds of explosives were tucked into a bag leaning against a telephone pole — a suspicious enough sight that the owner of a nearby kiosk phoned it in moments before the bag exploded. David Amoyal named his stand "A Blast of a Kiosk" after it was all but destroyed in 1994 by a Palestinian wearing a suicide vest. It's the kind of detonation Israelis learned to expect during the first years of the 21st century, when suicide attacks were almost routine.

But no one has blown himself up in Jerusalem since 2004. So effective has prevention been at thwarting serious strikes that three of the city's four most recent terrorist attacks involved vehicles: two were bulldozers taken on rampages, and the third a private car steered into a sidewalk thick with soldiers.

No organization claimed responsibility for Wednesday's attack, which appeared to be significant in itself. Israeli security officials said the bomb appeared to be the work of a small group, perhaps local self-starters able to operate below the radar.

"We have had hundreds of preventive successes in the last six or seven years, stopping attempts to launch attacks in Israel, and especially Jerusalem," a senior Israeli intelligence official tells TIME. "The aim to strike Jerusalem is still there, vividly so. The problem is the capability."

A major reason: the leadership of the Palestinian government in the West Bank vigorously opposes terrorism and cooperates closely with Israel to prevent attacks. Both Palestinian Authority President Mahmoud Abbas and Prime Minister Salam Fayyad issued condemnations shortly after the midafternoon explosion, and Israeli officials said Palestinian security was energetically engaged in the search for those who carried it out.

The other major Palestinian party, Hamas, is also known as the Islamic Resistance Movement. It remains committed to violent resistance against Israel and last weekend launched some 50 mortars into Israel from the Gaza Strip, the coastal enclave it governs. The Israeli military responded with attacks from the air, and with that Hamas leaders opted to restore the informal cease-fire that has been in effect since Israel invaded Gaza in December 2008, resulting in 1,500 deaths.

"Ah, mortars?" Hamas spokesman Taher al-Nunu told TIME on Monday, across a restaurant booth in Gaza City, when asked what precipitated the barrage. "Look, it was two years since the last war. Last month we had 17 martyrs" — the term Hamas uses for fatalities. He explained that the mortar launch into Israel was an overdue "reaction" but added that "we as a government spoke today and yesterday to all the military factions" and together agreed to resume the informal cease-fire. "Meaning there is no more launching of mortars after today," al-Nunu said.

Not all factions held their fire, however. The day after al-Nunu's statement, the military wing of the Islamic Jihad Party was locked into an escalating spiral with the Israel Defense Forces (IDF). The militants launched Grad rockets toward the cities of Beersheva and Ashdod, population centers rather than the farm fields that often absorb indirect fire out of Gaza. No deaths were reported, but Palestinian media quoted Islamic Jihad as saying the launches heralded a new era of targeting cities. The strikes came after an IDF drone launched a missile at a car carrying Islamic Jihad militants, killing all four. And in a separate incident, an IDF mortar landed in a yard, killing four from one family, including two children.

Israel apologized for the mistake, and in a gesture of political as well as humanitarian significance, offered to bring an 8-year-old boy to an Israeli hospital for treatment of his wounds. Hamas gave permission for the youth to travel through the no-man's land at the north of the Gaza Strip and into Israel through the extraordinarily elaborate Israeli security terminal that is the Erez Crossing.

Israeli officials say they take Islamic Jihad's threat seriously. "When the Israelis make a mistake and kill a family, or we target a senior Islamic Jihad terrorist, 1 million Israelis will be under the threat of rocket attack," a senior Israeli intelligence official tells TIME. "This is something we cannot accept."

Israeli politicians were also calling for action — first, for stronger military reaction to the missiles out of Gaza. Then, more loudly, for a tough response to the Jerusalem blast, even though security officials said there was no indication of who was responsible for it.

At Ben Gurion Airport, where he was preparing to leave for Moscow, Israeli Prime Minister Benjamin Netanyahu seemed to acknowledge the danger of events' spiraling out of control. No stranger to tough talk, he spoke of an "iron will" but in measured tones.

"We will act forcefully, responsibly and wisely," Netanyahu said, "to preserve the calm and security that have prevailed here over the past two years."

• Karl Vick and Aaron J. Klein / Jerusalem