Concerns about stockpiles of tactical weapons are coming into focus now that the United States and Russia have put into effect New START, a treaty which will cut stockpiles of strategic weapons.
Now the U.S. is hoping also to open preparatory talks with Russia on a possible reduction in tactical nuclear weapons, which are smaller battlefield arms such as short-range missiles, artillery shells, mines or gravity bombs. Such weapons have not yet been the subject of arms control agreements.
Strategic weapons, by contrast, have a longer range or larger destructive power.
Rose Gottemoeller, the chief U.S. negotiator of New START, visited Poland, Ukraine and the three Baltic states in recent days to hear how these countries view the issue of tactical weapons.
She said she has heard concerns across the region about Russian threats to build up its stockpile of tactical weapons in Kaliningrad, a Russian territory wedged between Poland and Lithuania.
"There is a generalized concern about Kaliningrad and Russian propensity to, every time a concern is aroused in Moscow, to say, well, 'time to bring something else to Kaliningrad,'" said Gottemoeller, who is assistant secretary of state for arms control.
"I would say it's a generalized concern among the countries of the region that I have visited this week."
Russia has not said whether it has nuclear weapons in Kaliningrad, but officials in neighboring countries are convinced they are there. Lithuanian Defense Minister Rasa Jukneviciene said this week that it's "no secret" that Russia has tactical weaponry in Kaliningrad.
Poland has expressed concerns in the past over threats by Russia to place missiles in Kaliningrad in reaction to a U.S. plan for a missile defense system in the region.
Polish Foreign Minister Radek Sikorski joined the debate on New START last year with a much-cited op-ed piece hailing the treaty as important to Europe's security. He called it a "necessary stepping stone" to future reductions in tactical nuclear arsenals.
"While we in Poland do not perceive an immediate military threat from Russia, most of the world's active tactical or sub-strategic nuclear weapons today seem to be deployed just east of Poland's borders, in speculative preparation for conflict in Europe," Sikorski argued. "The cataclysmic potential of such a conflict makes it essential to limit and eventually eliminate this leftover from the Cold War."
Some experts, however, note that it will be extremely difficult to persuade Russia to cut its stockpiles of tactical missiles. Russia believes that its large stock of tactical nuclear weapons balances NATO's superiority in conventional weapons, according to Jacek Durkalec, an analyst with the Polish Institute of International Affairs.
"The United States possesses limited means of inducing Russia to take part in negotiations on tactical nuclear weapons," Durkalec wrote in an analytical paper published Wednesday.
Gottemoeller said she disagrees with that argument and believes Russia could gain much from an arms control agreement on tactical nuclear weapons.