BONN, SEPT. 13 -- The two Germanys agreed last week on the broad outline of a long-term agenda for gradually lowering the political, psychological and physical barriers that have divided them since the onset of the Cold War.

The landmark visit to West Germany by East German chief of state Erich Honecker laid a diplomatic foundation for what could become the most substantial improvement in inter-German relations since the heady days of former chancellor Willy Brandt's Ostpolitic in the early 1970s.

Honecker and his host, Chancellor Helmut Kohl, achieved a tentative consensus on how to handle the two most emotionally charged issues in the inter-German relationship: East Germany's closed border, and reunification of the nation.

On the border, they signed a communique obliging East Germany to ease its travel restrictions. They also appear to have agreed that such a relaxation ultimately could lead to a situation where the communist government's border guards no longer shoot at its citizens when they try to escape to the West.

That was the message implicit in Honecker's unprecedented statement Thursday that the border is not "as it should be," and that it could become a "normal" one if the two Germanys continue the peaceful cooperation begun during his trip.

It was a dramatic statement, though carefully hedged, from the 75-year-old communist leader, who supervised the construction of the Berlin Wall in 1961.

The West German government, politicians and media commentators unanimously warned against "utopian" hopes regarding the border. But they strongly welcomed Honecker's declaration.

"Expectations have been raised more than was expected," an editorial in the Munich daily Sueddeutsche Zeitung said.

On reunification, which Bonn wants and East Berlin opposes, Kohl conceded that the issue "is at present not on the agenda of world history."

More important, he gave Honecker a red-carpet welcome. It showed that West Germany was willing to treat its neighbor as an equal in practice despite Bonn's official insistence that East Germany is only a separate "state" in a German "nation" that someday will be reunited.

Three bilateral agreements were signed in addition to the communique, and together they clear the way for a small but discernible jump in cooperation in diplomacy, science, trade, sports and cultural affairs.

Kohl reported to parliament that the results had been "considerable," and expressed optimism that "this will become clearer in the next months." Honecker said when he departed Friday that there had been "a row of positive results."

The inter-German thaw is risky for both sides, and it could easily be chilled, according to Bonn officials, diplomats and other observers.

In particular, a downturn in U.S.-Soviet relations would force the two Germanys to back off. Historically, they have been able to move closer only when the overall East-West climate was relatively relaxed.

East Germany's leadership probably will move cautiously to avoid raising expectations at home to the point where they become destabilizing. The attractiveness of Soviet leader Mikhail Gorbachev's reform program already has contributed to a spurt of small public protests in East Berlin in recent months.

For West Germany, it is possible that its flirtation with the East will tug it away from the western alliance in subtle ways. For instance, an increase in inter-German trade could run afoul of western restrictions on technology exports to the East Bloc.

Moreover, there is no guarantee that East Germany will follow through in a significant way on its commitment to relax travel restrictions. It will be able to do so only if the leadership believes that the economy is sufficiently strong to keep large numbers of people from emigrating.