President Donald Trump expressed concern that the strikes against Iran could lead to a new leadership that’s equally troubling to Washington as the regime the U.S. and Israel are fighting to topple.

Trump’s comments are likely to spur concerns on the administration’s endgame with the conflict well into its fourth day and retaliatory actions from Iran against Saudi Arabia exacerbating fears of further escalation across the region.

“I guess the worst case would be, we do this, and then somebody takes over, who’s as bad as the previous person, right? That could happen,” Trump told reporters Tuesday in the Oval Office. “You go through this, and then in five years, you realize you put somebody in who is no better.”