LONDON

Iran’s regime has been more resilient than anyone would have expected, said a former head of British foreign intelligence agency MI6, adding that options for the US and Israel are "pretty limited and not great."

"The reality is that the US underestimated the task, and I think as of about two weeks ago, lost the initiative to Iran," Alex Younger told The Economist Wednesday, mentioning that Iran has the "upper hand" in the war.

Younger said that Iran took some "good decisions" as early as last June about dispersing their military capability and delegating the authority for the use of those weapons, adding that this move has given them "significant extra resilience" against an incredibly powerful air campaign.

"In practice, the Iranian regime has been more resilient than I think anyone would have expected," Younger said.

He said that Iran has embarked on what he called "horizontal escalation," mentioning that firing rockets at anybody within range has been "a very good way of putting" a direct price on the US.

"They've understood the significance of the energy war and held the straits at threat and just globalized the conflict," said the former spy chief, adding that Iranians "played a weak hand pretty well."

Citing US President Donald Trump's statements on the war, he said that Iranians are in a war of existence, whereas America has embarked on a war of choice.

Touching on Iran's drone attacks, he said this has been an "almost perfectly executed military campaign" from the air, "you can't reduce the threat to zero."

"I think the options for the US and Israel are pretty limited and not great," he added.