The United States and the Czech Republic signed a landmark accord on Tuesday to allow the Pentagon to deploy part of its widely debated anti-ballistic missile shield on territory once occupied by Soviet troops.
The accord, the first of its kind to be reached with a Central or East European country, was signed in Prague by Secretary of State Condoleezza Rice and her Czech counterpart, Karel Schwarzenberg, despite strong opposition from Russia. It must also be ratified by Czech lawmakers, many of whom oppose it.
Russia warned on Tuesday that the accord could lead to a military response, which the Kremlin has previously threatened but never specified.
President Dmitri A. Medvedev and his predecessor, Vladimir V. Putin, who is now the Russian prime minister, had told the United States that the Kremlin saw a missile shield in this part of Europe as a threat to Russian security. Putin said it could even lead to a new Cold War.
But American and Czech officials said the system’s radar component, to be stationed south of Prague, would defend the NATO members in Europe and the United States against long-range weapons from the Middle East, particularly Iran.
“Ballistic missile proliferation is not an imaginary threat,” Rice said Tuesday after meeting with the Czech prime minister, Mirek Topolanek. She said Iran continued to work toward a nuclear bomb, along with long-range missiles that could carry a warhead.
Rice is on a European tour that includes Bulgaria and Georgia, but not Poland. The United States hopes to base 10 interceptor missiles there, but the governments in Warsaw and Washington have so far failed to reach agreement on the terms.
Unlike the Czech Republic, the Polish center-right government led by Donald Tusk has taken a tough negotiating stance. In return for hosting the interceptors, Poland has asked the United States to modernize Polish air defenses so that the country can defend itself against incoming short-range and medium-range missiles.
The accord with the Czech Republic is not without its problems.
The deal signed on Tuesday does not ensure that the radar system will be built immediately or that the next American administration will stick to the project.
Negotiations are still taking place on a second treaty that deals with the legal status of American troops to be deployed at the planned radar base. Both treaties must be ratified by Czech legislators, many of whom are skeptical about the project, while the public is largely opposed.
Topolanek’s coalition government does not have enough seats to assure support for the plans and may need opposition votes. Legislators from the Green Party, the government’s junior coalition partner, have indicated they may block the proposals, and opposition parties have demanded a national referendum. About two-thirds of Czechs oppose the radar deployment, according to opinion polls.
“Ratification will be difficult,” said Jiri Schneider, program director at the Prague Security Studies Institute. “The missile defense plan has sparked a national debate about how exposed we want to be on the international stage.”