Alireza Nader writes: The Iranian regime is hardly cheering Hagel on, despite what some of his critics say. Yes, Hagel sounds cautious about a U.S. bombing campaign against Iran’s nuclear facilities, but such a campaign isn’t what keeps the Iranian supreme leader, Ayatollah Ali Khamenei, up at night. An American strike would spur the Iranian public to rally around the flag and buck up a wobbling, wheezing theocracy — and an Israeli strike would do so in spades.

The Iranian leadership’s real worry is not American planes but Iranian protesters. Their deepest anxieties revolve around a Persian version of Tahrir Square, a replay of the 2009 Green uprising that wasn’t ended by the regime’s violent repression. Strange as it may sound, the Islamic Republic is a lot more frightened of the imprisoned Iranian human rights activist Nasrin Sotoudeh than it is of Israeli Prime Minister Benjamin Netanyahu.

As such, Hagel’s nomination was greeted in Tehran with a shrug, not a sigh of relief. The Islamic Republic hardly thinks that with Hagel nominated, it’s off the nuclear hook. Iran’s leaders see U.S. “hostility” as institutionalized and systematized, not produced by partisan politics or individual appointments. As Hossein Salami, a top-ranking Revolutionary Guards officer, said of Hagel, “We view the United States as a political and ideological system driven by its strategic interests rather than by individual politicians.”

That was true even in the transition from George W. Bush to Barack Obama. The Islamic Republic greeted Obama’s election in 2008 with mixed emotions. On the one hand, the Iranian regime worried that Obama’s barrier-breaking achievement and inspiring life story might appeal to the average Iranian in a way unmatched by any previous U.S. president.

On the other, the Iranian regime continued to believe that its lifelong rivalry with the United States is the result of flatly irreconcilable differences: what it sees as Washington’s unshakable opposition to the Iranian revolution, unqualified and limitless support for Israel, and insistence on competing with Iran for influence over the Middle East.

If Obama’s election didn’t change Tehran’s view of U.S. policy, it’s hard to see how Hagel’s nomination could. After all, America’s war-weariness is no secret, and it’s hardly limited to Vietnam veterans such as Hagel. Iranian decision-makers can read The New York Times and watch CNN like anyone else, and they understand the reluctance, both among America’s people and elites, to go to war against Iran over its nuclear program.