ARABS and Jews, alike. Costa Ricans. Eastern Europeans. Come one, come all--that's the message which the Kennedy School of Government has been extending these days. Unless you're Michael S. Dukakis, that is.

The Kennedy School, long the resting home of choice for exiled Democratic politicos, has begun to diversify into the area of international relations. With a spate of new programs aimed at bringing public servants from around the world to Cambridge, the school the Kennedys build has targeted an international audience for its latest public relations offensive.

At the dedication of the school's new Middle East Institute, lame duck Dean Graham T. Allison '62, who actively disclaims any and all suggestions that he will be traveling to Washington should Dukakis win in November, said that the center represented "another major step forward in the internationalization" of the Kennedy School.

In addition to the new Middle East program, which will bring social workers from Israel and several Arabic nations to Harvard for the year, the Kennedy School recently announced a Costa Rican fellowship program named in honor of Nobel Laureate Oscar Arias and several other programs which will allow Eastern Europeans and Israelis to study here.

But what exactly does this facelift mean for the Kennedy School? Does the school plan to concentrate all its interests in the field of diplomacy and international relations? Is it aiming to become the new stomping ground for European and Third World bureaucracies? Will it now boast proudly of the Cambridge-Cairo connection in the same way that once it heralded the Boston-Washington link?

THE answer is, or at least should be, no. At least, not if one looks to the Kennedy School's original mission, or the functions it has filled in its last 25 years. When the school was renamed in honor of President John F. Kennedy '40, the founders decreed that Harvard's School of Public Administration would be training an elite new corps of public servants to serve the nation.

In practice, that meant the Kennedy School soon acquired a reputation for turning out a new breed of technobureaucrats with advanced degrees and progressive, but pragmatic, ideas about the role of government. The federal government, that is.

But in the course of the new "internationalization" drive, the Kennedy school has been shying away from the active national political role it has cultivated over the past 25 years--and in the process, publicly severing the ties which bind it to Democractic candidate Dukakis.

Aggressive non-partisanship in this most political of election years is a difficult task for a school of government, but Kennedy School professors and administrators, schooled in the art of public relations, seem to be trying their hardest to dispel rumors that the Duke has his own think-tank on the Charles.

One apocryphal story has it that when professors planning to move to Washington for the Dukakis Administration line up for the ride, the Greyhound bus they expected will be replaced by a jeep, and a small one at that.

So why now, in an election year that pits former Kennedy School lecturer Dukakis against Vice President George Bush, has the focus suddenly turned outward?

After all, Dukakis came to the Kennedy School after his shocking defeat in the 1978 gubernatorial race and re-emerged four years later as an invigorated and victorious politician. And when he returned to the State House he brought with him so many Kennedy School colleagues that Allison was forced to personally negotiate a hiring freeze with the governor.

Something has obviously changed since then. It's not that the number of Kennedy School scholars advising Dukakis has decreased, but that the governor has somehow fallen out of official favor.

In general, professors at the school of government love to talk to the press, love to see the phrase "Harvard University's John F. Kennedy School of Government" in print. Some say that when people at the Kennedy School are bored, they count the number of references to the school inserted into the Congressional Record. But if someone wants to write about the school's links to Dukakis, they try to downplay the whole thing.

CYNICS would say that the school's high-profile scholars and administrators have given up on the Dukakis campaign. When queried now about the Massachusetts governor, school officials invariably respond by saying that President Reagan brought in more Kennedy School professors than any of his Democratic predecessors.

But, as all good students of politics know, it's not the numbers which matter but the public's perception of the numbers. And it seems now as though the Kennedy School, in its attempt to divert attention from the political successes of one of its former lecturers, has adopted a "new direction" that is nothing but a cloak with which to disguise the fact.

If the Kennedy School of Government plans to become an international center, then call it a school of diplomacy or of foreign relations. Otherwise, observers should ask: Why all the fuss?