UNITED NATIONS – As Rafik Hariri was laid to rest yesterday in Beirut, Lebanon, there were signs that his assassination on Monday has rocked neighboring capitals, with Damascus and Tehran reaffirming that their regimes form “one front,” flexing their muscles – and exhibiting some fear of outside pressures.

The goal of a Tehran visit by Syria’s prime minister yesterday was to project strength to world, send a message to Washington and Jerusalem, and allay Syria’s own public unease, officials and observers in the region and abroad said.

The reaffirmation of the alliance followed international and Lebanese outrage since Hariri’s assassination. “I suppose this is a sign of uneasiness in Syria,” a former American ambassador in Damascus, Richard Murphy, told The New York Sun.

There were signs of unease in Tehran as well. A mysterious explosion near Iran’s nuclear plant in Busher was explained several times by the mullah regime in what sounded like a hurried and confused reaction. The conflicting signals rattled stock markets and raised speculations about an Israeli or American attack.

Before settling on an explanation that the explosion was merely a blast from construction work at a dam, Iranian officials and press outlets reported that the cause was a missile shot from an aircraft, and later that a fuel tank from an Iranian plane fell to the ground. The intelligence chief, Ali Yunesi, also said publicly that American spy drones were spotted over Iranian nuclear facilities.

Pentagon and State Department officials denied any involvement in the explosion, as did American allies. “Nobody is talking about invading Iran, and Iran is not Iraq,” Prime Minister Blair told Britain’s Channel Five television. “But there is a serious issue about Iran trying to develop nuclear weapons capability.”

Also in London, Israel’s foreign minister, Silvan Shalom, said that Iran is but six months away from acquiring the know-how to assemble nuclear weapons. Israeli officials, however, also denied any involvement in the blast.

Israel Radio’s Farsi service director, Menashe Amir, told the Sun that even if the cause of the blast was indeed construction work, the reaction and conflicting reports signaled “great nervousness among the leaders of Iran, who fear an Israeli or American attack on their nuclear facilities.” The reaffirmation of the Syrian-Iranian alliance was another indication of those fears, he added.

A day after America recalled its ambassador in Damascus for urgent consultations in the aftermath of the Hariri killing, Iran’s vice president, Mohammad-Reza Aref, hosted Syria’s prime minister, Naji Al-Otari.

“Iran will share its experiences, those of sanctions in particular, with Syria given the situation Damascus is faced with at the present time,” Mr. Aref said according to the Iranian News Agency IRNA. Mr. Al-Otari reciprocated. “My visit to Tehran is in line with promoting the level of mutual transactions,” he said. “We are going to discuss cooperation in areas such as transportation, oil, housing, irrigation, energy, and industry.”

American lawmakers and officials said they intend to increase Syria’s isolation and pressure its Baath regime economically, but IRNA noted that Iranian businessmen have invested $600 million Syria recently and quoted Mr. Aref’s announcement that Iran intends to reach a level of $3 billion a year in “mutual economic relations.”

“There is nothing new” in the Syrian-Iranian alliance, Mr. Murphy said, adding that the visit to Tehran could have been intended for internal consumption, a signal by President Assad’s government “to their own public, to say that somebody loves us.” Though not new, however, the public announcement was perceived in America and Israel as significant.

“Unlike the group of moderate Arab states we saw in Sharm Al-Sheikh, we now see the opposite in Tehran,” a Foreign Ministry spokesman, Mark Regev, told the Sun from Jerusalem, referring to the recent summit in Egypt, where Prime Minister Sharon met with the Palestinian premier, Mahmoud Abbas. Iran and Syria are “states that oppose Israeli-Arab reconciliation and are partners on the wrong side of the war on terror,” he added.

One Israeli intelligence source who asked not to be named said that the Syrian-Iranian terrorist proxy organization Hezbollah, which is based in southern Lebanon, has increased its pressures on Palestinian Arabs in the territories since Yasser Arafat’s death and the signals by Mr. Abbas that he intends to put an end to the armed struggle. He cited in particular the fact that since Mr. Abbas’s election, Hezbollah has doubled the “prize money” awarded to families of Palestinian suicide bombers, to $100,000 from $50,000.

More menacing for Israel is Iran’s stride toward nuclear capabilities. Mr. Shalom yesterday merely repeated in public a message that Israeli officials say he has been repeating in private in practically every meeting with foreign dignitaries, warning that Iran is fast nearing the point of no return, after which its scientists’ know-how will be enough to make Tehran a de facto nuclear power.

“The question is not if the Iranians will have a nuclear bomb in 2009, 10 or 11,” he said in London. “The main question is when are they going to have the knowledge to do it. “Israel believes that “in six months from today they will end all the tests and experiments they are doing to have that knowledge,” he added.

The head of the International Atomic Energy Agency, Mohamed elBaradei, told reporters on Tuesday in Vienna that the European-led diplomacy is working.

“Over the last 15 months, we have made good strides in understanding the nature and scope of [Iran’s nuclear] program,” he said, urging continuation of the diplomacy led by Britain, Germany, and France.

President Chirac yesterday paid his condolences to Nadia Hariri, the widow of the slain former foreign minister whose funeral turned into huge anti-Syrian rally. The presence of Mr. Chirac in Lebanon, France’s former colony, was a strong signal to Syria.

However, one Washington-based advocate of democracy, the president of the Reform Party of Syria, Farid Ghadry, said that Syrian Baathists still assume they are winning, and that their display of alliance with Iran was part of a strategy to fight international isolation. “Don’t be surprised if in the next few days a deal with Russia will be announced publicly,” he told the Sun.