WASHINGTON -- Ever since Iranian President Mahmoud Ahmadinejad struck a deal with Venezuelan dictator Hugo Chavez for weekly air service between the nations' capitals, American officials have worried that Iranian-backed terrorists could reach to the rim of Latin America, pick up fake Venezuelan passports and sneak into the United States.
Now, with growing talk of a pre-emptive Israeli attack to slow Iran's suspected nuclear arms program, Iran has threatened that it would retaliate across the globe. And its easy access to the Western Hemisphere has the U.S. particularly concerned.
The commercial service between Tehran and Caracas by Iran Air and Conviasa Air Venezuela, including a stop in Damascus, Syria, is so secretive that there's confusion among intelligence agencies about whether the flights are continuing. Israel believes they are; the U.S. isn't so sure.
Nevertheless, American fears are elevated.
"Some Iranian officials -- probably including Supreme Leader Ali Khamenei -- have changed their calculus and are now more willing to conduct an attack in the United States in response to real or perceived U.S. actions that threaten the regime," James Clapper, director of National Intelligence, warned the Senate Intelligence Committee in his latest threat assessment.
If that attack comes, experts see it being staged by Iranian operatives who have entered the U.S. through Latin America.
"There's pretty much of a general consensus within the intelligence community that Iranian-backed cells providing financial support to Hezbollah could easily convert to operational cells and light up the place," says U.S. Rep. Mike McCaul, a Republican whose district stretches from Austin to Houston.
McCaul, chairman of investigations for the House Committee on Homeland Security, led a seven-day fact-finding mission across Latin America last week. "From our observations on this trip, the Iranian threat to the United States is very real and it would be difficult to defend against all of these operatives."
Iranian retaliation would likely fall to pre-positioned operatives drawn from the ranks of the 15,000-strong Iranian Revolutionary Guards Quds Force or 10,000-member, Iranian-backed Hezbollah based in southern Lebanon.
McCaul said Hezbollah is fundraising with impunity in the tri-border area surrounded by Paraguay, Argentina and Brazil, where some 30,000 Lebanese expatriates and immigrants live among a population of 800,000.
He said enterprising businesses there are being required to tithe as much as 2 percent of gross revenues to the Lebanon-based terrorist organization.
Yet the suspected terrorist haven largely is ignored by the three adjacent countries.
"Authorities downplay the threat," McCaul said. "They talk about trans-national crime. But they don't want to talk about terrorism. If you use the T-word, they pucker up."
The Iranian-backed suicide bombing of an Israeli tourist bus in Bulgaria on July 18, killing five Israelis and wounding 30, is the latest sign Tehran remains ready to strike abroad.
"Iran has methodically cultivated a network of sponsored terrorist surrogates capable of conducting effective, plausibly deniable attacks against Israel and the United States," reports the Pentagon's latest assessment of Iran's military power.
There also are signs that Iranian agents are forging ties with murderous, multibillion-dollar Mexican drug cartels.
"Iranian operatives are stepping into power vacuums," said Rep. Henry Cuellar, D-Laredo, a member of the House Committee on Homeland Security who made the trip. "If you were Iran and you wanted to retaliate against the United States you would go through the backyard. Latin America is America's backyard."
Federal authorities unmasked an alleged Iranian Quds Force plot last fall that featured attempts by a naturalized American born in Iran to enlist a member of the Mexican narco-terrorist group Los Zetas in a $1.5 million scheme to kill the Saudi ambassador to the U.S.
Manssor Arbabsiar, a Corpus Christi resident arrested Sept. 29 at John F. Kennedy International Airport, faces trial in New York in October on multiple charges stemming from the alleged plot to assassinate Adel Al-Jubeir by bombing his favorite restaurant in Washington.
"We have to presume that Hezbollah cells are present and being fortified while awaiting orders from Iran," retired Marine Col. Timothy Geraghty warned Congress last fall after the assassination plot came to light.
Operatives are here?
Congressional investigators working for the GOP majority estimate there are now "at least hundreds of Hezbollah operatives" in the U.S., said Rep. Peter King, R-N.Y., chairman of the House Committee on Homeland Security.
Most suspected Iranian operatives are believed to have come into the U.S. through the 327 ports of entry, including airports, border crossings and maritime ports. A handful may have surreptitiously crossed the 1,969-mile Southwestern border. Of 59,017 non-Mexican citizens arrested crossing the U.S.-Mexico border in 2010, 14 came from Iran and 11 from Lebanon.
"We are constantly working against different and evolving threats involving various terrorist groups and various ways they may seek to enter the country," Homeland Security Secretary Janet Napolitano told Congress in late July.
Yet suspected terrorists have "from time to time" slipped across the border, Napolitano conceded.
Her comments reflect continued partisan differences over the Iranian threat. GOP-drafted legislation backed by 82 co-sponsors -- including nine Texas Republicans in the House -- would require the Obama administration to "use all elements of national power to counter Iran's growing presence and hostile activity in the Western Hemisphere."
The White House remains more circumspect.
Iran may have rapidly expanded across Latin America in recent years by setting up 11 embassies and 17 cultural centers.
But the State Department's annual report on terrorism concluded "there were no known operational cells of either al-Qaida or Hezbollah in the hemisphere."