Abstract
The US is a nation of immigrants and the diversity of the constituencies is represented in the functioning of its political institutions. Indeed, not only is it considered legitimate for the interest groups to interfere with the decision making process, but the foreign policy does not constitute an exception and is not beyond their reach.
The legitimacy of organized public interest groups is not obvious. In theory, the national interest is one for all in the country, and therefore the same in all parts of it; in practice, a congressman campaigning in his district does not see it identically to the President, as the former has to consider the specific interests of a very narrow constituency . The dangers of factions in government were perceived by the Founding Fathers who also acknowledged their inevitability in a republic: "Liberty is to faction what air is to fire", wrote James Madison. Later, in the XIX century John Calhoun gave the theoretical justification of their role: policies do not affect everyone equally; there is an imbalance between the few who are organized and the many who are inattentive. Special interests are therefore a means for the citizens to get involved and be represented, thereby reducing the risk of a tyrannical majority abusing its power over a minority. Public interest groups act as a counter power in the political system and have their place in the checks and balances. Moreover, such groups are themselves balanced by the creation of competing ones who oppose their claims. Thus, clashes of interests occur and the government's mission is indeed to reconcile them and make the best decision for the nation.
