After Iranian president Mahmoud Ahmadinejad's recent defiant announcement about installing 3,000 uranium enrichment centrifuges in Natanz, signs of an emerging leadership crisis in Iran have appeared. They expose the power group of Ahmadinejad and his Revolutionary Guard supporters (usually backed by the supreme leader, Ali Khamenei) and the more "pragmatic," though no less extreme in their final goals, clerical leadership. In a speech on January 8 Khamenei warned against any withdrawal from the Iranian nuclear program by any person or Iranian official in the present or in the future. Recently there have been rumors that Khamenei is seriously ill, and may die soon. His speech seems to be the proclamation of a dying man's will. Simultaneously, former president Akbar Hashemi-Rafsanjani, the recently elected chairman of the Experts Assembly, which has the authority to select the supreme leader, had an intensive two-day meeting with the top-level ayatollahs in the holy city of Qom. The most important issue discussed was the selection of a new supreme leader. Rafsanjani asserted in his speech in Qom that the Experts Assembly should choose the leader soon, in order to keep the regime safe and avoid a future power struggle after his death. ACCORDING to article 111 of the Iranian constitution, the Experts Assembly may change the supreme leader should he become incapacitated. Until this happens, the president, Ahmadinejad, the head of the Supreme Court, Ayatollah Mahmoud Hashemi Shahroudi, and an ayatollah from the Constitution Guardian Council, probably Ayatollah Ahmad Jannati, would collectively carry out the duties of the supreme leader. This would lead to control of the neo-hard-liners over the Iranian leadership. The ongoing discussions among the Iranian leaders indicate that Khamenei's speech has caused concern, and objections from most of the mullahs. Their main objection could be the eligibility of a dying leader to make significant decisions on issues that may put the Islamic regime in danger. Since most of the members of the Assembly of Experts, all of whom are clergy, are pragmatists, and their own security and that of the Islamic regime is their main concern, it is likely that they will not let the fate of the regime be determined by a sick and dying man. THE ACUTE leadership controversy was revealed on a live TV interview with Rafsanjani on February 10. The program was dedicated to recollections of Iranian leaders from the period of the Iranian revolution, which is now celebrating its 28th anniversary. Rafsanjani, who is an obvious contender for the position of the supreme ruler but does not yet have the support of the Assembly of Experts, seized the opportunity to divert the interview to promote himself and attack his opponents. He expanded on his religious background and scholarship since this is a point of weakness being used against him by his opponents. He then told about the controversy in the first period of the Islamic republic, when high-level Iranian mullahs and he especially opposed the appointment of the first Iranian president, Abol-hassan Banisadr, who was not a cleric, in opposition to the desires of Ayatollah Ruhollah Khomeini. Khomeini proclaimed that the mullahs should be engaged in spiritual leadership only, and not be involved in political power positions. After one year Khomeini admitted that Rafsanjani's circle was right. Serving then as the spokesman of the parliament, Rafsanjani led the parliament to impeach Banisadr on the grounds of incompetence. Khomeini endorsed the decision, and Banisadr was replaced. Rafsanjani alluded to the present situation in which Ahmadinejad, who is not a mullah, is supported by the supreme leader Khamenei, but does not have the support of the mullahs of Qom. This interview was the strongest attack by Rafsanjani against Ahmadinejad since the beginning of his presidency. This probably indicates that Rafsanjani was successful in gaining support against Ahmadinejad among high ranking mullahs. Ahmadinejad's followers responded to Rafsanjani's interview by claiming that Ahmadinejad is not Banisadr, and Rafsanjani's power isn't what it was 26 years ago. A FEW days after the interview, on February 15, Hossain Marashi, Rafsanjani's confidant and brother-in-law, suggested starting an investigation of the Iranian parliament because of the damage Ahmadinejad has caused to Iran's foreign relations, exposing Ahmadinejad's political incompetence and breach of trust. The Iranian parliament can impeach the president by a two-thirds vote. The dispute heated up with a new speech by Khamenei on February 18. He reiterated that the nuclear program must be continued and declared that anybody inside the regime who thinks that the nuclear activity should be stopped because of international threats must be "blockheaded" and does not understand the situation. The next day, an opposition reformist group in Iran - Mojahedin Enghelab Eslami - published a statement calling for the cessation of uranium enrichment before the deadline of the UN Security Council and protesting that Iranian newspapers are not permitted to debate the risk involved in nuclear activity and the danger of war. This is the first time a legal party within the regime had officially expressed an objection to the nuclear program. This is a significant event, even though the opposition is powerless in the Iranian regime. One only need add to this picture the unpredictability and bravado of Ahmadinejad and his extreme Revolutionary Guard followers in order to appreciate the inflammatory nature of the situation. THE CONCLUSION derived from this string of events is that, due to an emerging leadership vacuum, the Islamic regime of Iran is marching toward a historic crossroads, with substantial risks and instability. One may also conclude that the recent military power moves directed by the American president, as minimal as they are, are starting to have an affect. The West must act now, with full force and vigor, and for the sake of world peace, so as not to miss the narrow window of opportunity and further destabilize this critically dangerous regime. 'John Samson' is the pseudonym of an Iranian scientist now in exile, previously connected with top Iranian political and scientific figures.