The idea of introducing a presidential system to Israel has been raised in the public discourse, this time as a possible plank to be incorporated in Kadima's party platform. President Moshe Katsav has, meanwhile, appointed a committee of experts to look into the possibility. Pursuing this suggestion would be a major mistake. It is obvious that the parliamentary system, as it now operates in Israel, has many flaws. But none of them would be cured by the transition to a presidential system. There are a number of arguments marshalled by supporters of moving to such a system. First and foremost is a wish for a strong executive not dependent on pressure from many political parties, some small and interested only in the promotion of their narrow agendas. This is an illusion. In order to be elected, presidential candidates would also need the votes of the adherents of these parties. Just as happened in our experiment with the direct election of the prime minister, candidates would have to woo the small parties in order to get the votes of their supporters. Once elected, the president would have to live up to these commitments in ministerial appointments as well as in budgetary allocations. Any president would be beholden to these special interests because without them he could not be reelected. MOREOVER, once elected, the president would still depend on the Knesset and its fractured party structure to get his budget approved and his legislative agenda carried. Even a quick look at the US system confirms that the American president is dependent on Congress for approval of the administration's policies. Only presidents in authoritarian systems - Russia or Egypt, for instance - are free from the rough and tumble of political bickering, and obviously no one wants to see such a "presidential system" in Israel. For all its failures, the Israeli system does, at the end of the day, deliver, and the Gaza disengagement showed how courageous leadership can overcome built-in limitations of the system. Over decades, Israel has been able to carry out most of its national agenda - waging war and peace, ingathering of the exiles, developing the country's economy - all under very difficult conditions. Powerful leaders have built coalitions and carried out daring programs - not without difficulties. It's hard to think of a single essential policy that has not been carried out because of alleged structural faults of the system. A presidential system would not solve the problems of economic inequality, corruption and a top-heavy bureaucracy; nor could it better address our troubles with the Palestinians. There is an understandable desire to free decision-makers from the competing voices and pressures of society, yet such hopes are both dangerous and an illusion. No system is perfect, yet it is not an accident that all democracies - with the exception of the United States and, up to a point, France - have parliamentary systems. In the US, because of its enormous size and federal structure, the role of the president is attuned to its specific character and circumscribed by a well-tried constitution. Our system needs reform - mainly dealing with how parties are structured - but tinkering with its parliamentary foundations is a dangerous game. If it ain't broke - don't fix it. And despite its enormous burdens and problems the Israeli system ain't broke. The writer is professor of political science at the Hebrew University of Jerusalem.