UNITED NATIONS — After the final chapter of the 2006 war between Israel and Hezbollah ended yesterday with celebrations in Lebanon and mourning in Israeli cities, Jerusalem officials and scholars warily eyed a possible future assault by the terrorist organization deployed on Israel’s northern border.

Like a shark that cannot stop swimming, Hezbollah is not expected to rest on its laurels, several Israeli intelligence sources and government officials said yesterday. Even as it celebrates a prisoner exchange yesterday that is largely perceived as sealing a victory for the Iranian-backed organization, its military planners calculate their next moves. Those may be conducted against Israel, Jewish targets abroad, or other targets related to the larger Iranian struggle with the West.

The bodies of Ehud Goldwasser and Eldad Regev — whose kidnapping by Hezbollah in a cross-border raid in June 2006 has triggered a fire exchange known in Israel as the Second Lebanon War — were returned yesterday in black coffins, ending a chapter many Israelis consider their most humiliating battlefield defeat. Jewish mourning prayers were read in major cities, as the Goldwasser and Regev families prepared for today’s heart-wrenching funerals.

In Lebanon, Hezbollah officials yesterday taunted their enemy and celebrated the return of a convicted child killer, Samir Kuntar, who has become an instant Lebanese hero of the “resistance.” Kuntar, along with four other Lebanese men held in Israeli jails, was sent to Lebanon by Israel after the bodies of Goldwasser and Regev were positively identified. The bodies of 199 Lebanese and Palestinian Arab terrorists and fighters were also returned in the exchange.

“The question is what Hezbollah will do next,” a Jerusalem official, who spoke on condition of anonymity on security matters, said yesterday. “They have 40,000 missiles aimed at Israel. Their military power was almost tripled since the end of the war, even under the watch of the United Nations. Israel, according to media reports, killed their top military planner, and Nasrallah explicitly said they would retaliate. One thing is for sure: Hezbollah is not going to relax now just because they could declare victory in Beirut.”

The Jerusalem Center for Public Affairs’s Jonathan Dahoah Halevi said, however, that he doubts Hezbollah will act now on the Lebanese front. “The first mission of Hezbollah, which is an arm of the Iranian revolution, is to take Lebanon over,” Mr. Dahoah Halevy, who is a former intelligence researcher, said.

He said he doubted that with that mission in mind, the organization currently has an interest in drawing fire to Lebanon from Israel. After the February 12 killing of the organization’s top operations commander, Imad Moughnieh, Hezbollah’s top leader, Hassan Nasrallah, specifically said that Hezbollah would not limit its reaction to Lebanon. Also, Mr. Dahoah Halevy said, as part of the policy of exporting Iran’s religious revolution, it is intensely converting native tribes in Venezuela and elsewhere in Latin America to Shiite Islam. “Hezbollah is an international terrorist organization and an official arm of the Iranian revolution,” he said.

“We cannot be defeated,” Mr. Nasrallah said yesterday, hugging Kuntar during a mass Beirut reception organized by Hezbollah. It was a rare public appearance for Mr. Nasrallah, who has been in hiding since the June 2006 kidnapping of the two soldiers, fearing an Israeli assassination. “The Israelis did not know what happened to the soldiers, and this was an important power position,” he said.

Over the two years since the kidnapping, Hezbollah steadfastly refused to release any information about the two men. The lack of knowledge raised emotions expressed in the Israeli press, increasing the pressure on the Israeli government to pay any price for the return of the two soldiers.

Karnit Goldwasser, the young wife of one of the kidnapped soldiers, conducted a campaign for their release that turned her and other family members into household names in Israel and abroad. Yesterday she was said by her father, Omri Avni, to be finally stricken by an “emotional storm.”

“A stranger would not understand this,” Prime Minister Olmert said, highlighting the Israeli society’s nature as a family. President Peres contrasted the sorrow in Israel with the celebrations in Lebanon about a killer of a four-year-old. “Where is the moral victory? Where is the humanistic defeat?” he said. “Lebanon should be ashamed.”

Releasing the kidnapped soldiers was one of the Israeli government’s reasons for launching the 2006 war and became part of the U.N. resolution that had ended it. Yesterday’s deal was negotiated by a German intelligence official who was authorized by a U.N. secretary general, Kofi Annan, as a U.N. “facilitator.”

“I appreciate this contribution,” Secretary-General Ban said yesterday at a press conference in Germany, adding, “I’m very much encouraged by the exchange of prisoners. I hope this will be the beginning of many to come in the future.” He expressed the hope that the agreement would hasten the release of Gilad Shalit, the Israeli soldiers who was kidnapped near Gaza by a Hamas-affiliated group shortly before the Regev and Goldwasser kidnapping.