For those who didn't follow, the speculated frontrunner before this man's appoinment was Saeed Jalili who was thought to have been even more hardline than Larijani. He didn't get the job, but when it comes to the new guy it doesn't get anymore hardline than being one of the orchestrators of the 1983 bombing of the US embassy in Beirut.
Every assassination Israel has committed thus far has brought in more and more hardliners as replacements, with a greater sense of self-preservation of course. If the war ends with Iran's current government structure intact, the country will essentially become the Middle-East North Korea.

