As the ongoing U.S. strike on Iran entered its tenth day, reports surfaced Sunday that the beleaguered Islamist regime had selected Mojtaba Khamenei to be the country’s next supreme leader following the death of his father Ali Khamenei on February 28 as the result of an American missile attack. But President Trump maintained that if the next Iranian leader does not get U.S. approval, they’re “not going to last long.”

Mojtaba Khamenei, who is 56, was reportedly selected after a “strong” vote from a group of clerics. The vote appeared to dash the hopes of a swift end to the mullah’s regime in Tehran, as Khamenei is widely seen as an Islamist hardliner in the line of his father, “a Shi’ite cleric with a power base among the security forces and their vast business empire.” Trump told ABC News that the next Iranian leader is “going to have to get approval from us,” but the president did not specify what kind of scenario would enable an opposition leader to emerge who the U.S. would approve of.

Doubts remain as to whether an opposition force will rise up to challenge the regime, as the U.S. has hoped would result from its intensive airstrike campaign. An analysis from The Wall Street Journal on Sunday pointed out that airstrikes alone have rarely if ever resulted in the downfall of a regime in previous military operations, noting that Germany’s defeat in World War II, Iraq’s defeat during “Desert Storm” in 1991, and Yugoslavia’s defeat in Kosovo in 1999 all resulted from a combination of air power and ground forces. Former Air Force Secretary Frank Kendall stated that “Air power alone can do a lot of things well, but regime change is not one of them.”

From the outset of the Iran operation, the White House has maintained that there are no plans to send U.S. ground troops into Iran. But on Saturday, Trump suggested that ground troops could be used if there was “a very good reason.”

Reports indicate that if the U.S. is aiming for the Islamist regime to relinquish power, ground forces will likely be necessary. As noted by WSJ, “the attacks have yet to remove the core structures of the regime.” So far, there have been no signs of defections from the upper echelons of Iran’s military, nor have there been major strikes within Iran’s industrial base, particularly in the oil industry. Analysts like Alan Eyre, a former diplomat who served on the U.S. nuclear negotiating team with Iran, doubt that the regime will buckle absent a much more extensive U.S. ground campaign. “We’re not seeing it, and we’re unlikely to see it. The IRGC and other elites benefit the most from the status quo and would rather fight than switch.”

So far, Iran’s response to the U.S. strikes has been fierce, as they have launched dozens of missiles and drones at perceived enemies across the Middle East region. Over 12 countries have been targeted by the Islamist regime, including “eight bases with a U.S. presence and four commercial ships.”

Observers like Israeli Ambassador to the United States Yechiel Leiter say that the frenzied response from the regime is further proof of the necessity of the joint U.S-Israeli military operation.

“I don’t know how anybody could still have a doubt about the necessity for this operation,” he emphasized during “This Week on Capitol Hill” over the weekend. “After the past couple of days, Iran is shooting ballistic missiles indiscriminately [at] all of its neighbors and beyond its neighbors into Europe.” He further argued that the regime’s continued obstinance to pursue nuclear weapons even after the U.S.’s Operation Midnight Hammer further illustrates the need for the strikes. “[L]et’s imagine for one moment that all of those missiles now hitting around the Gulf states and into Europe were tipped with a nuclear warhead. Imagine where we’d be today. So the actions, the operation underway between Israel and the United States, led by President Trump, is saving not only the Gulf, Israel, and U.S. allies, but the U.S. itself.”

Leiter went on to insist that once the Islamist regime in Tehran is overthrown, it will allow the U.S. to focus its attention toward the larger threat in Beijing.

“Once [the regime] is defeated, the moderates will be able to come to the surface and live side by side with the West, with Judeo-Christian civilization,” he underscored. “… Once this is complete and we have created peace in the Middle East and regional cohesion and cooperation between all the Gulf states among themselves and with Israel, the United States is going to be able to move their military assets to the Far East, where there’s the real threat coming out of China for regional hegemony. So this is very, very key to the future not only of the region but the future of the United States.”

Leiter concluded by predicting that the Iranian people will eventually unite to be allies of the West, as they once were before the Islamist Revolution in 1979. “Eighty percent of the Iranian people reject this regime, but they’ve been living under the murderous boot of the ayatollahs now for 47 years, and their freedom has been entirely deprived of them,” he highlighted. “And once we move into an era where the ayatollahs no longer dominate all the minorities of Iran, they’ll come together.”