Three-week defense exercise, postponed from spring, will be largest of its kind to date, simulate missile defense scenarios.

Israel drill
The US and Israel will commence the largest-ever joint air defense drill of its kind in Israel on October 21, an army source said on Tuesday.

The exercise, named Austere Challenge 12, was originally scheduled for last spring but was postponed due to regional tensions with Iran.

On October 14, large numbers of American soldiers are expected to begin arriving in Israel, where they will set up aerial defense positions on Israeli territory and on US Navy vessels off the Israeli coastline.

The three-week drill will simulate various missile defense scenarios, and is expected to end with a live-fire interception of a decoy incoming Patriot missile.

One of the objectives of the drill is to facilitate the rapid deployment of US missile defense systems to Israel and test their ability to operate in conjunction with Israeli defense systems during a conflict.

The IDF Spokesman's Office said Tuesday that "the US and Israel hold regular joint exercises between the militaries.

These exercises are planned ahead of time and form part of the routine training program, aimed at improving mutual operations."

The AC12 drill forms "another milestone in the common strategic relations between the US and Israel," the office added, stressing that the drill is "unrelated to any pinpoint developments in the region."

At the end of August, the US said it would decrease the original number of American forces due to take part in AC12. An Israeli defense source said at the time that the exercise will still be the largest of its kind to date, adding, "Defense cooperation between Israel and the US has never been better."

In 2009, the IDF and US European Command held the Juniper Cobra 10 air defense exercise, which involved 1,400 US soldiers and the same number of IDF soldiers.

The drill went through three phases: a field training exercise; computer simulation command post-exercise to test interoperability capabilities; and a live-fire exercise involving a Patriot missile interception.

The exercise was hailed as a success by Israeli and American military commanders.

Separately, the Home Front Command is expected to hold its sixth annual national emergency drill on October 21. The drill will focus on testing responses to earthquakes.