Amid smoldering tension with Iran, U.S. forces are deploying in Israel for a strategically important ballistic missile defense exercise, considered one of the most complex ever conducted by the two allies.

Juniper Cobra 2009, the latest in a biennial series that began in 2001, will focus on how well U.S. and Israeli forces can integrate and operate together in any future confrontation with the Islamic Republic.

U.S. officials insist that the exercise, due to commence Monday and end next Friday, is routine. "This exercise is not related to or in response to any world events," the U.S. Embassy in Tel Aviv stressed.

But the maneuvers have taken on added importance since the U.S. administration scrapped plans to deploy land-based ballistic missile defense systems in Eastern Europe in August. The focus will now be on U.S. naval forces in the Mediterranean and the North Sea.

"Military exercises like Juniper Cobra do not take place in a vacuum," according to the Texas-based security consultancy Strategic Forecasting.

"The 2009 exercises were scheduled for spring. It seems that the schedule changed and regardless of the reason, the timing of these exercises will ratchet up already sky-high tensions between the West and Iran."

The exercises, it added, were "certainly a show of force at a politically opportune moment."

It is also possible that the unusually extensive U.S. participation this year is intended to reassure Israel, which considers Iran's nuclear and missile programs to be an existential threat.

Israel has threatened to launch unilateral pre-emptive strikes against Iran, while Washington, seeking to pursue a diplomatic solution, has urged caution. The sizeable U.S. deployment for Juniper Cobra 2009 could be meant to convince Israel to stay its hand.

There has been speculation that the Americans will leave behind some missile units when the maneuvers end to bolster Israel's defenses.

Some 1,000 troops from the U.S. European Command, headquartered in Stuttgart, Germany, and 15 warships from the U.S. 6th Fleet will participate in Juniper Cobra to work alongside Israelis in countering computer-simulated missile attacks from Iran and its Arab ally Syria, as well as from Lebanon and the Gaza Strip.

The Israelis have long feared that if Iran launched a ballistic missile strike at the Jewish state, it would be accompanied at some point by shorter-range attacks from Syria, Hezbollah in Lebanon and Hamas in Gaza.

Israel is in the process of building a multilayered defense shield against all calibers of missiles, dominated by the high-altitude, long-range Arrow-2 anti-ballistic system, whose development over the last decade has been largely funded by the Americans.

But the U.S. military, whose bases and installations in the Middle East are also potential targets for Iranian missiles, has found that Israel has become a handy testing ground for its own ballistic missile defense systems.

This dates back to the 1991 Gulf War, when Israel came under fire from Scud-type missiles unleashed by Iraqi leader Saddam Hussein. The U.S. Army deployed Patriot missile batteries in the Jewish state to bolster Israel's own Patriots.

Juniper Cobra will involve limited live-fire exercises. The Israelis will test their upgraded Arrows during Juniper Cobra, while the Americans will test three of their BMD systems.

The Patriot Advanced Capability-3 batteries will link with an advanced U.S. X-band radar unit, capable of detecting and tracking multiple incoming missiles. That unit, manned by U.S. personnel, was set up at the Nevarim air base in the southern Negev desert in 2008.

The Americans will also deploy the Theater High Altitude Area Defense system, which works in conjunction with PAC-3 to intercept missiles in the final phase of their trajectory.

The 6th Fleet ships, which will be an integral part of the new U.S. BMD network, will complete the triad of U.S. BMD systems with the Standard Missile-3 aboard upgraded Aegis guided-missile cruisers and destroyers.

"This will not be the first time different elements of the U.S. BMD architecture have been tested together," Stratfor noted, "but there will be noteworthy developments nonetheless: Operating with foreign systems could offer considerable insight into the true state and deployability of the current American BMD architecture."