WASHINGTON, March 11. /TASS/. As US stockpiles of missiles and shells are depleted repelling attacks by Iranian forces, America's ability to protect its troops, assets and allies is being eroded, said Vali R. Nasr, an Iran expert at Johns Hopkins University.

According to the expert, "It’s surprising how quickly they [Iranian military] learned and implemented lessons from the 12-day war." "They learned that what we are lacking is defensive capabilities, like interceptors, THAAD missiles and Patriots," he told The New York Times.

In an interview with the newspaper, two US military officials expressed concern that the Pentagon does not know about all Iranian missile launch sites. They added that the Islamic Republic had kept "many" missiles in reserve "to strike at important battlefield targets like the American radars."

Last week, Pentagon officials reported at a closed briefing to the US Congress that Iran retained about 50% of its missile and launcher arsenal.