U.S. and Iranian tension

Iran recently threatened to close the Strait of Hormuz, through which 40 percent of all oil produced globally is transported, in response to the imposition of tougher economic sanctions by the United States and the European Union on its oil trade.

Last week, the United States sent a letter to the Iranians informing them that closing the strait would be considered a red line, and that the United States would respond militarily if need be.

Meanwhile, Chairman of the U.S. Joint Chiefs of Staff Martin Dempsey is reportedly to arrive in Israel later this week for talks with Israeli government and military officials. While the exact schedule has not been issued, it is expected that the talks would focus on Iran.

Analysts say Iran doesn't have the military capability to launch a missile that could reach the United States. However, Israel, which Iranian President Mahmoud Ahmadinejad has called to be wiped of the map, is well within range.

Ahmadinejad's threats, combined with the continuation of a nuclear program, has led to a vociferous discussion in Israel among both former military officers and politicians alike, over the possibility of launching a military strike to take out Iran's nuclear infrastructure.

But according to some reports, the United States is seeking an Israeli confirmation that it won't launch such an attack.

But, on the other hand, the argument could be made that Israel' s vagueness over its intentions serves the United States, since it can point to Israel and say that "more and tougher sanctions are needed otherwise there is no telling what Israel might do."

Israeli Prime Minister Benjamin Netanyahu, who has been encouraging the United States and the Europeans to impose tougher sanctions, has been giving conflicting statements about the effectiveness of the sanctions over the last couple of days.

Last week he said that they were working, but on Monday he was quoted as saying that they weren't.

The United States has over the last month been trying to convince buyers of Iranian oil to switch to other suppliers in the Gulf region, in order to increase the pressure on Iran and to alleviate the price hike that would follow a ban on Iranian oil.

This has put Iran in a tricky spot, according to Karmon, " because the sanctions are really working, and if there are sanctions, but the oil price isn't up - then Iran losses all its cards."

Military strike

Karmon argued that there are two ways that one can interpret the decision not to hold the drill now, and how that may or may not be connected to a possible Israeli air strike on Iran.

"One is that the decision between the two sides about the Iranian threat and what to do about it is at a stalemate, and the Americans don't want to appear to push the Israelis to attack Iran, " he said.

"On the other hand, one can say that the Americans know that during this period Israel is going to attack, so they want to be far away," Karmon added.

The commonly held view among military experts that have studied possible scenarios for an Israel air strike, is that Israel lacks the military capability to undertake a comprehensive operation, successfully.

This is mainly because the current type of fighter jets that the Israeli Air Force uses lack the long-range capability to fly to Iran without having to refuel in midair in both directions, which is a very risky procedure.

Many of Iran's nuclear installations are also spread out across the country and some are buried deep underground.