FOR THE PAST five years, I have been in charge of the Palestine Information Office in Washington. The purpose of my office is to try to explain to the American public and its representatives in government the need to recognize the legitimate demands of the Palestinian people.

Now the United States government is trying to close our office, trying, in effect to silence the voice of the Palestinian people in Washington and the United States. It is ironic that in the same year that the United States is celebrating the 200th anniversary of its Constitution that the American government is trying to silence another people's cry for freedom and the right to self-determination and independence.

It is important for Americans to know that the initial demand to close the Palestine Information Office in Washington and the PLO United Nations Observer office in New York was made by Israeli Prime Minister Yitzhak Shamir in 1986. This demand was immediately adopted by the American Israeli Public Affairs Committee, the umbrella for the Israeli lobby in Washington.

Secretary of State Shultz resisted their demand for over a year, during which time the Justice Department was ordered to investigate the office for any possible violation of law. When that investigation was concluded, the Justice Department flatly stated that the office was operating totally within the requirements of the law. Thereafter, as recently as last May, the State Department reaffirmed in a letter its long-standing policy that so long as the Palestine Information Office was complying with the law, closing it would violate the First Amendment.

This is what America is supposed to be all about. Someone as powerful as the secretary of state could disagree with me, but at the same time stand up for my lawful right to speak out on a political issue. But it seems that the upcoming elections have caused the secretary -- and many others -- to weaken their commitment to the Constitution.

The Palestine Information Office in Washington has been in existence since 1978, during which time it has been properly registered under the Foreign Agents Registration Act with the U.S. Department of Justice. Its function has been to explain, to any American who asks, the Palestinian side of the Arab-Israeli conflict -- a side which gets very little hearing in this country.

For years, the Palestine Liberation Organization has asked for recognition and dialogue with U.S. officials, hoping for some sort of breakthrough in negotiating an end to the Israeli occupation of the West Bank and Gaza Strip and for recognition of the national rights of the Palestinian people.

The U.S. has rejected all these overtures. In fact, because of a unilateral promise Henry Kissinger made to the Israel government in 1975, U.S. officials refuse even to talk to someone from the PLO about anything, including peace in the Middle East.

On Sept. 15, when a State Department official appeared in my office with documents ordering the closure of the office, I was shocked. I was, of course aware of the proposed legislation pending in both the U.S. House and the U.S. Senate which would have declared the PLO a terrorist organization -- it has never been so declared -- and would have decreed that both my office and the U.N. Observer office in New York be closed, in violation of U.S. treaty obligations. But I assumed most people would share my view that the sponsors of those bills -- Kennedy, Simon, Dole, Grassley, Mikulski, Kemp and others -- were simply performing for the Israeli lobby.

That the State Department would reverse itself and jump to the head of this line of politicians was something I hadn't contemplated. To accomplish the deed, the State Department had to resort to an underhanded trick. My office was upgraded to the status of a foreign mission -- a status it has never had and not asked for -- then summarily ordered closed within 30 days.

Just like that. No hearing. No explanation. No opportunity to argue the case before a judge. No thought for the office's employes and their families. It was ordered closed by the same State Department that has been demanding that the Sandinistas allow Nicaragua's opposition newspaper, La Prensa, to re-open. But it closes an American office without due process of law.

What has made the Constitution of the United States such an enduring document is that even if a majority of the public is opposed to someone's exercise of free speech, or of religion, those rights cannot be abrogated. In this case, there was no majority demanding that the Palestine Information Office be closed -- not even a minority. Only the Israeli government and its band of lobbyists who do not want Americans to hear a Palestinian point of view.

Beyond the shredding of the Constitution by this act, the result of this turn-around by the State Department is, of course, to openly establish that on matters of Middle East policy where Israel and the United States disagree, Israel ultimately wins. When this happens, any semblance of neutrality or independence by the United States is destroyed and its position as an arbitrator of peace is undercut.

The Palestine Information Office has no choice but to litigate the government's unconstitutional action in the courts. The American Civil Liberties Union has agreed to accept this case and to argue it on constitutional grounds. This struggle is likely to be long and complicated. But I don't believe that we are arguing only on our own behalf. Defending freedom of expression is everyone's obligation.

Hasan Abdel Rahman, born in Ramallah in 1944, is a naturalized American citizen.