Vice President-elect Joseph R. Biden Jr. has said he thinks the Bush administration should explicitly assure the Iranian leadership that it would not seek a regime change, as one part of the incentives and sanctions that the United States and Europe have been offering in hopes of prying Iran away from its nuclear program.

Mr. Obama, for his part, has been a little less clear.

In an interview in September he said, “I think it is important for us to send a signal that we are not hell-bent on regime change just for the sake of regime change, but expect changes in behavior, and there are both carrots and there are sticks available to them for those changes in behavior.”

European officials said that the Obama advisers have played their cards close to the chest. “They come in, they listen and they say, ‘Thank you very much,’ ” said one official of a European embassy in Washington. He spoke on the condition of anonymity because he was not authorized to speak publicly on the issue.

The French foreign minister, Bernard Kouchner, said over breakfast with reporters in Washington this week that he thinks “the personality of Barack Obama can make a difference” when it comes to Iran. But Mr. Kouchner also urged that Mr. Obama exercise caution, using a speech at the Brookings Institution to warn against undermining the carefully plotted, but so far unsuccessful, transatlantic effort to rein in Iran’s nuclear ambitions.

Israel has been pushing, too.

A senior Israeli official said that the Israeli government is in touch with Mr. Obama’s close aides, in particular with Dennis B. Ross, President Clinton’s former envoy to the Middle East. “For us, it’s Iran,” the official said, adding that Israel wants to make sure that Mr. Obama will tackle the Iran issue as soon as he takes office. “We can’t afford a vacuum.”

Russia, too, has already made a proposal, one that is close to Moscow’s heart. Last Friday, Deputy Foreign Minister Aleksandr V. Grushko said that Russia would not deploy missiles in Kaliningrad, a Russian enclave that borders Poland, if Mr. Obama were to scrap the Bush administration’s planned missile defense shield. Mr. Obama has said that he supports a missile shield, provided that the technology is workable and cost efficient.

As for the Taliban, it seems unlikely that Mr. Obama will be acceding to its call for American troops to be pulled out of Afghanistan. He said during the campaign that, to the contrary, he would increase the number of American combat brigades deployed there.