A senior official from ​a Paris-based Iranian opposition group said on Thursday that the U.S.-Israeli war on Iran would not topple the clerical leadership, arguing that only a popular uprising backed by internal resistance could do so.

Almost two weeks of bombing have killed around 2,000 people in Iran, including Supreme Leader Ayatollah ​Ali Khamenei, and damaged much of its military and security apparatus.

Iran has responded in ​kind, throwing global energy markets and transport into chaos and spreading the ⁠conflict across the Middle East, while the Islamic Revolutionary Guard Corps has tightened its grip ​on power and threatened to crush any unrest.

“The 12-day war in June, and the current ​war, now in its 12th day, proved that bombings cannot overthrow the regime,” Mohammad Mohaddesin, head of foreign policy at the National Council of Resistance of Iran (NCRI), told a news conference.

“Even if you have 50,000 ​armed soldiers on the ground, you need the support of the Iranian people. You need a ​popular uprising. The combination of this 50,000 or 20,000 or any other number with a popular uprising, ‌then ⁠you have this power to overthrow the regime.”

Mohaddesin said he did not consider a deployment of U.S. ground troops realistic.

The NCRI, also known by its Farsi name Mujahideen-e-Khalq, was listed as a terrorist organisation by the United States until 2012.

It is banned in Iran, and it ​is unclear how much ​support it has there. ⁠However, along with its bitter rival, the monarchists backing Reza Pahlavi, the exiled son of the toppled shah, it is one of the few ​opposition groups able to rally supporters.

Mohaddesin acknowledged that his group alone could ​not bring ⁠down the system. But he said mass protests, like those that raged in January until they were bloodily quashed, would resume once bombing stopped, and could eventually shift the balance.

“I cannot say ⁠how ​many months or a year, but … this is the ​track of overthrowing the regime,” he said.

Israeli officials have said that one of their objectives is to weaken the ​security apparatus so that Iran’s people can take control of their own destiny.