A visit to Lebanon this week by Iran's president will give a welcome boost to powerful Shiite ally Hezbollah, one of Tehran's most crucial sources of foreign influence, and will include a provocative jaunt to the border with archenemy Israel.
Mahmoud Ahmadinejad's trip is a bold demonstration by Iran that it is undeterred by U.S. attempts to isolate it and roll back the clout Tehran has built up around the Middle East through its alliances with militant groups like Hezbollah and its accelerating nuclear program.
The Iranian president is also wading into Lebanon's worst political crisis in years by putting Tehran's weight behind Hezbollah as the group feuds with its rivals in Lebanon's Western-backed political coalition. That tension threatens to bring down the fragile unity government in which both serve and, in a worst case scenario, push the well-armed Hezbollah to violently seize control of Beirut as it did in a similar showdown two years ago.
In a sign of how sensitive the visit is, Hezbollah's rivals in government released a statement saying Ahmadinejad is seeking to transform Lebanon into "an Iranian base on the Mediterranean."
Iran is pouring cash into Lebanon. Most of it goes to Hezbollah, but in a sign that Tehran is seeking to extend its support base in the country, some of the cash is helping rebuild homes in southern Lebanon's Shiite heartland that were damaged in the 2006 war with Israel.
"I urge the Lebanese people and the Palestinians to welcome the president of Iran," Hezbollah leader Sheik Hassan Nasrallah said in a weekend speech, as Iranian flags and Ahmadinejad posters popped up along Beirut's airport road.
Iran is seeking to prove its influence in the region is strong despite Washington's threats that Tehran's nuclear program will lead to more sanctions and more isolation. Iran has pursued an aggressive foreign policy in recent weeks: visiting Lebanon at a time of national tumult, stopping by Syria just after a U.S. delegation on his way to the United Nations last month and ridiculing U.S. efforts to forge a Mideast peace deal.
Iran has maintained a strong hand in Lebanon through Hezbollah, which the U.S. designates as a terrorist organization and which boasts a heavy arsenal of rockets capable of reaching deep inside Israel.
Hezbollah is part of Lebanon's government, sharing power with Western-backed parties led by Prime Minister Saad Hariri. But the militant group, whose arsenal is separate from that of the national army, is Lebanon's strongest armed force _ a fact that has drawn new concerns in recent weeks as the political crisis here deepens.
A U.N. tribunal investigating the 2005 assassination of former Prime Minister Rafik Hariri is expected to indict members of Hezbollah as soon as this month, which many fear could lead to violence between the Shiite force and Hariri's mainly Sunni allies. The slain leader is the father of the current prime minister.
Washington, too, has come out against the trip. Last week, U.S. State Department spokesman P.J. Crowley said Secretary of State Hillary Rodham Clinton raised concerns about the visit with the Lebanese president, Michel Suleiman.
"We expressed our concern about it given that Iran, through its association with groups like Hezbollah, is actively undermining Lebanon's sovereignty," Crowley said in Washington.
Washington is at odds with Iran over its nuclear program, which it fears is aimed at making weapons, and with a military buildup by Tehran that it believes threatens the United States' Arab allies in the region as well as Israel. Iran says its nuclear activity is only for producing energy.
During Ahmadinejad's Oct. 13-14 visit, he plans to stop at sites including Bint Jbeil, a border village that was bombed during the 2006 Israeli-Hezbollah war. It is barely two and a half miles (four kilometers) from the Israeli border.
In his speech Saturday, Nasrallah denied Lebanese media reports that Ahmadinejad planned to hurl stones at the border. In the past, it was common for Lebanese to throw stones toward the border in celebration of the 2000 withdrawal of Israeli troops from southern Lebanon after 18 years of occupation.
Hezbollah's military strength has long worried the U.S. and its close ally Israel.
In August, U.S. lawmakers in Congress said they were concerned about weapons falling into the wrong hands and put a hold on $100 million of the $720 million in military aid that U.S. administrations have provided to Lebanon's ill-equipped army since 2006.
Iran promptly offered to step in and fill the gap and slammed the U.S. for offering help with strings attached.
Nasrallah suggested that Iran's cash infusions help all Lebanese, including through the rebuilding of war-damaged homes in the south.
"Hezbollah does not trust the Lebanese government's bureaucracy," Nasrallah said, "and the Iranians paid in cash."
The message got through to many Lebanese.
"Ahmadinejad's visit is meant to extend a helping hand, without anything in return," said Zeinab Mrad, a 50-year-old Shiite woman from Khiam village, a Hezbollah stronghold in southern Lebanon.