Regarding your story "US Special Squad Killed Benazir" (The Nation, May 18), we take exception to allegations that the US government had anything whatsoever to do with the tragic assassination of Pakistan's former Prime Minister, late Benazir Bhutto. We have deep admiration for Ms. Bhutto and are offended and outraged that your newspaper would republish this especially repugnant brand of spurious and unsubstantiated rumor. Regrettably, these baseless, sensational and third-hand allegations have been repackaged and republished without any responsible attempt at either verification or solicitation of comment from an official source of United States government. This, with out any byline story, was distributed by a Pakistani wire service, which in turn allegedly quoted an unidentified Arab broadcast organization, which in turn allegedly quoted a single source (a journalist), who in turn relied on comments that were allegedly erased from an interview that took place almost two years ago. Apart from the circuitous and obscure web of allegations in this story, the most troubling of all is the complete failure to provide an opportunity for the accused party, the United States government, to refute these claims. Balance, accuracy, and fairness in reporting are the pillars of a free and responsible press. In this case, all three of these elements were absent. Your readers should - and do - expect a higher standard of journalism but instead have been served what amounts to little more than unfounded vicious gossip. The US government has repeatedly and publicly demonstrated its support for freedom of the press. However, it is always important to remember that with freedom comes responsibility. The people of Pakistan face serious issues and should be able to rely on a free press for accurate news and information. It is our hope that The Nation will rise to meet these challenges and serve the people of Pakistan in the spirit of both truth and responsibility. -ANNE. W. PATTERSON, Ambassador of United States of America, Islamabad, May 18. Even though the newspaper holds no brief for the news item the US Ambassador has referred to in her letter, it was based on an interview of Seymour Hersh, and was circulated by a wire agency. All Pakistani newspapers carried the report. The point made by Ambassador Patterson is well taken. The paper is well aware of the meaning of press freedom and understands its responsibility. It needs no lecture on ethics of journalism. We are also carrying Mr Hersh's clarification in today's edition.-Editor