A U.S. intelligence assessment completed shortly before the United States and Israel launched a war in Iran had determined that American military intervention was not likely to lead to regime change in the Islamic Republic, according to two people familiar with the finding.

The National Intelligence Council’s assessment in February concluded that neither limited airstrikes nor a larger, prolonged military campaign would be likely to result in a new government taking over in Iran, even if the current leadership was killed, according to the two people, who spoke on condition of anonymity to describe the classified report.

The determination undercuts the administration’s assertion that it can complete its objectives in Iran relatively quickly, perhaps in a matter of weeks. The administration has asserted that it was not seeking regime change in Iran, even as the strikes have taken out many figures in the Iranian leadership and President Donald Trump considers whom he would like to see lead the country.