The pressure is growing and the threats are escalating against Iran. The U.S. Congress is increasingly expressing impatience. Both major U.S. presidential candidates keep making it clear they see war as an option to end Iran's nuclear program. Yet direct talks between Iranian and European negotiators have broken down. And Iran's uranium-enrichment program continues.

The question is, why has nothing moved Iran to compromise?

It's not that Tehran is determined to pursue the program at any cost. Iran brought the enrichment program “to an abrupt halt” in 2003 after the U.S. invaded Iraq, David Albright, president of the Institute for Science and International Security, told the House Armed Services Committee June 20. Instead, it may simply be that, this time, Tehran does not take the military threat seriously.

“We don't think the Iranians really believe that [the U.S. will strike],” Stephen Rademaker, a member of the National Security Project (NSP), recently told the House Armed Services Committee. But once the U.S. became bogged down in the Iraq conflict, it restarted its weapons effort.

“The Revolutionary Guard holds that power and will dictate what takes place,” says former Sen. Charles Robb, a co-chairman of the NSP. Washington may have to divert resources from the new Asia-Pacific strategy to the Middle East to ensure Iran takes a military threat seriously, he says.

The Senate also weighed in.

“We must conclude that Tehran is using the talks as a cover to buy time as it continues to advance toward nuclear weapons capability,” says a June 15 letter from 44 U.S. senators to President Barack Obama. “Allowing Iran to gain this capability is unacceptable.” The letter was organized by Sens. Robert Menendez (D-N.J.) and Roy Blunt (R-Mo).

As an absolute minimum to continue talks, Iran must shut down the Fordo uranium enrichment facility near Qom, freeze all uranium enrichment above 5% and ship all uranium enriched above that level out of the country, the letter says.

“We urge you to . . . focus on significantly increasing the pressure on the Iranian government through sanctions and making clear that a credible military option exists,” it says.

The facilities targeted for attack, which include missile and missile-engine development, are run by the specialized Qods Force. It is an extralegal Iranian Revolutionary Guard organization that remains beyond the control of Tehran's elected government, say U.S. and Israeli officials.

Israeli President Shimon Peres, in Washington to receive the Medal of Freedom, was asked if he would be in favor of a military bombing strike.

“Not a threat—more than a threat,” he said in a Washington Post interview. “The Iranians must be convinced this is not just a tactic.”

He contends that the U.S. must lead such an attack with international support. Even the cyberattacks were combined operations with intelligence gathered from many nations; additional intelligence and funding came from the U.S., and long-term development and a permissive legal environment were provided by Israel, U.S. cyberspecialists tell Aviation Week.

“The U.S. is the leading force in the world today,” Peres says. “There are things Israel cannot do that the Americans can. The U.S. never acts alone. It always goes in coalition. Obama is building a coalition.”

On the other hand, many Iranian militants say they want the U.S. or Israel to bomb their country so they will be justified in launching retaliatory attacks, Uzi Rubin, former head of Israel's missile defense organization, tells Aviation Week.

Yet, “if the question is [an Iranian] bomb or bombing [Iran], the answer is clear: bomb,” Vice Premier Moshe Ya'alon, a former Israel Defense Forces chief of staff and director of military intelligence, said in a June 15 interview with Israel's Haaretz Magazine. However, “if anyone, no matter who, decides to take military action against Iran's nuclear project, there is a high probability that Iran will react . . . and will fire missiles at Israel.” Moreover, if a delivery system is available, “Iran today has enough enriched uranium to manufacture five atomic bombs. Within a year, it will have enough uranium for seven or eight. It has the capability to enrich uranium to above 90% within two or three months. In less than six months, it will be in possession of at least one primitive nuclear device—a dirty bomb.”

The Qods Force also is establishing itself in South America. New York's district attorney, for example, is investigating links between Iran and Venezuela aimed at developing unmanned aircraft, explosives and weapons components. Venezuela also has imported top-of-the-line weapons, including Russian-made, man-portable anti-aircraft weapons such as the formidable SA-24. Iran has provided the same weapons—taken from Libya and transported to Hezbollah in Lebanon and Hamas in Gaza, say Israeli officials.

U.S. intelligence agencies have been tracking camouflaged shipments, financial transfers and the construction of installations in Venezuela, all under the supervision of the Qods Force, says the Madrid-based ABC newspaper.