The reluctance is particularly strong among some NATO members, like Spain, Italy, France and Germany, with major business and energy ties to Russia. They would like to see a quick return to the status quo ante.

But in a division reminiscent of the debate over “New Europe” and “Old Europe” during the Bush years, NATO members near the Russian border say that era is over.

“The fundamental understanding of security in Europe has now collapsed,” said President Toomas Hendrik Ilves of Estonia. “Everything that has happened since 1989 has been predicated on the fundamental assumption that you don’t change borders by force, and that’s now out the window. Political leaders need to recognize that the old rules no longer apply.”

The surveillance fleet is owned by NATO, with money and staffing contributions from 17 nations. It is under the direct control of the top NATO commander, Gen. Philip M. Breedlove of the United States Air Force, who can deploy the planes without consulting with member states. General Breedlove became NATO commander in July, and he has been outspoken about the new threat from Russia.

The Obama administration has so far rejected suggestions, including some from senior officials in the State Department, to significantly increase the tiny presence of American or NATO troops, or the supplies of military equipment, in countries bordering Russia. The White House does not want NATO to pour fuel on the fire, a senior official said, but it did recently commit American troops for temporary exercises in Poland and the Baltics. But the total number is tiny: about 600 paratroopers normally based in Italy.

“This is very symbolic reassurance, very carefully calibrated to ratchet up if need be,” said Sean Kay, a former Pentagon adviser on NATO. Washington does not want to feed the notion of the Russian president, Vladimir V. Putin, that the West is determined to encroach on traditional Russian turf, he said. But some argue that for Washington to do so little is an invitation to Mr. Putin to do more.