After months of relative passivity, Egypt effectively declared war in mid-April on Iranian-backed terrorist groups operating in its backyard, executing an unprecedented wave of arrests of alleged terrorists, smugglers and arms-makers linked to Hezbollah and Hamas.

In the most dramatic action, Cairo announced April 8 that it had arrested 25 Egyptian, Lebanese, Sudanese and Palestinian men — reportedly including seven Israeli Arabs — accused of membership in a Hezbollah cell that was said to be plotting acts of sabotage in Egypt. Also arrested in separate operations April 10 were 15 Egyptians accused of manufacturing rockets for Hamas in Gaza, as well as three Egyptians accused of planning to smuggle cash to Hamas.

The rapid-fire series of actions represent, in various ways, departures from standard Egyptian security practices, numerous observers said. Taken together, they appear to indicate a new and more belligerent stance toward the regional threats Egypt sees emanating from Iran and its terrorist allies.

“This looks like part of a larger regional issue,” Middle East scholar Stephen P. Cohen of the Israel Policy Forum said of the arrests. “There is a fear in Cairo that the Hezbollah operation is part of an Iranian attempt to weaken the regime in Egypt. And the Egyptians are not going to play gently with that.”

The arrests of the smugglers and rocket-makers represent, in and of themselves, a sharp turnabout in Egypt’s strategy toward the Hamas regime in Gaza. Israel has long accused Cairo of failing to take meaningful action against smugglers bringing arms and cash into Gaza from Egyptian-ruled Sinai. According to the Israeli daily Haaretz, just last month, a former deputy director of Israel’s Shin Bet security service charged in an academic article, published in an international journal, that Egypt was regularly seizing smugglers’ goods but failing to seal off their smuggling tunnels or to make arrests.

The capture of the accused Hezbollah cell represents an even more drastic turn of events. The Lebanese Shi’ite militia is not known to have staged operations outside Lebanon since 1994, when it is believed to have bombed a Jewish community center in Argentina. Today, its political wing is a member of Lebanon’s governing coalition, lending a potentially explosive diplomatic aspect to any planned operation against a fellow Arab state.

Hezbollah’s secretary general, Hassan Nasrallah, denied in an April 10 broadcast that the organization was planning attacks within Egypt. Nasrallah acknowledged the presence in Egypt of a Hezbollah member, Sami Shihab, but he said Shihab was there to lend military assistance to Hamas in Gaza, not to attack Egyptian targets.

The denial only fueled Egyptian anger, since the acknowledgment of a Hezbollah presence on Egyptian soil — for the first time in the organization’s history, according to Israeli military experts — was seen as a violation of Egypt’s sovereignty.

Egypt’s initial statements on the Hezbollah arrests indicated that the men had been engaged in surveillance of villages along the Sinai-Gaza border, Sinai coastal resorts popular with Israeli tourists and spots along the Suez Canal. Among other things, the suspects reportedly admitted to interrogators that they had rented shops in Port Said, at the northern end of the canal, to observe ship movements. Arab newspapers quoted Egyptian officials saying that the group was planning to blow up the canal, potentially dealing catastrophic damage to the Egyptian economy.

Moreover, Egyptian officials indicated that another 24 suspected cell members were still at large, prompting security alerts that kept thousands of Israelis away from the popular resorts during the peak Passover season.

In the days following the announcement, Egypt left no doubt that it viewed the events as a major diplomatic crisis. State-controlled media mocked Hezbollah, at one point calling Nasrallah “the monkey sheikh.” The semi-official Egyptian newspaper Al-Ahram charged that Hezbollah had moved into Sinai because it had wanted to attack Israel, but was afraid to operate across the Lebanese border because it incurred massive losses after a cross-border raid touched off the 2006 Lebanon War.

Escalating the confrontation, Egyptian foreign minister Ahmed Abul Gheit placed the blame for the alleged plot directly on Iran, charging in an interview published April 14 that Iran was seeking to expand its influence in the region by using Hezbollah to destabilize the Egyptian government.

“Iran and Iran’s followers want Egypt to become a maid of honor for the crowned Iranian queen when she enters the Middle East,” Abul Gheit told the pan-Arab daily Asharq Al-Awsat.

Relations between Iran and Egypt have been poor for decades. Iran broke diplomatic relations with Egypt in 1979, after Egypt gave asylum to the deposed Iranian shah following Iran’s Islamic revolution. Relations were never restored.

Tensions have increased in recent years, however, as Iran’s regional ambitions have grown following the fall of Iran’s traditional enemy, Iraqi dictator Saddam Hussein. Beginning in 2006, Iran and Hezbollah began directing a steady stream of vitriolic rhetoric at Egypt for failing to back Hezbollah and Hamas in their conflicts with Israel.

The rhetoric reached a fever pitch earlier this year, after Egypt remained neutral during Israel’s three-week assault on Hamas in Gaza and refused to let Palestinians enter Sinai to flee the fighting. In January, Nasrallah accused Egypt’s president, Hosni Mubarak, of having given Israel a “green light to attack Gaza.”

“The Egyptians have felt very strongly that not only their regional status but their domestic stability has been threatened by the sort of martyrs-vs.-traitors rhetoric that has been directed against them,” said Hussein Ibish, a research fellow at the American Task Force on Palestine. “During the Gaza war, you had spokesmen saying, implicitly or even outright, that the Egyptian people should rise up.”

The Gaza war appears to have been a pivotal moment in Egypt’s national security thinking. The presence of the Hamas regime in Gaza, on Egypt’s northern border, represents a constant threat because of fears that Hamas will join hands with its ideological sister movement, the Muslim Brotherhood, which Egypt sees as its most threatening domestic opposition.

It is to counter this threat that Cairo has kept its border with Gaza sealed off ever since Hamas took over the district in June 2007. Cairo also has worked continuously to push Hamas and the rival Fatah movement, which now controls the West Bank, into a unity government that Egypt hopes will be led by Fatah leader Mahmoud Abbas, president of the Palestinian Authority.

The results have been frustrating. Fatah has flatly refused to join forces with Hamas as long as the Islamic movement refuses to recognize Israel and swear off violence, and Egypt has been unable to convince Hamas to formally embrace any formula that would amount to recognizing Israel, even implicitly.

“There is a strong sense within the Egyptian government that the situation in Gaza has become incredibly dangerous,” Ibish said. “There’s the danger of domestic unrest because of dissatisfaction with the closure. There’s the danger of the tunnels making the border area a flashpoint. There’s a strong sense that some parties in Israel would like to maneuver Egypt back into responsibility for Gaza, which would create a direct link between the fundamentalist regime in Gaza and the fundamentalist opposition in Egypt. From every point of view, it’s a serious national security threat.”

With the appearance of the Hezbollah cell on Egyptian soil, those threats became reality, and Egypt was forced, at last, to act.