* Mixed reaction to scrapping shield plans
* Analysts say security unaffected
* Some worry about message it sends to E.Europe and Russia
(Updates with quote from Czech Prime Minister, paras 4&5)
By Gareth Jones and Jan Lopatka
WARSAW/PRAGUE, Sept 17 (Reuters) - A U.S. decision to scrap missile defence plans in Poland and the Czech Republic does not threaten the NATO allies' security, but some fear it shows U.S. regional commitment is cooling while Russia is more assertive.
President Barack Obama announced on Thursday he was dropping a plan to deploy interceptor missiles in Poland and a radar system in the Czech Republic; parts of a missile shield intended to protect the United States and its European NATO allies against possible attack from Iran.
Moscow, the region's former overlord, had opposed the plan.
Czech PM Jan Fischer saw no cause for concern in the news.
"There are no reasons for changes in our relationship with the United States. We are on a perfect level on a bilateral basis and in the framework of NATO. We have strong allies and strong partners," he said in Brussels on Thursday.
Iwona Jakubowska-Branicka of Warsaw University said the region should approach the decision calmly. "The U.S. president has changed and so has U.S. foreign policy. I don't think the enemy is just outside our gate," she said. Both Obama and his predecessor George W. Bush, whose administration strongly pushed the shield plan, had argued that it was not aimed against Russia, noting that 10 interceptors would be no match for Moscow's vast nuclear arsenal.
But the Kremlin viewed the shield as a direct threat to its national security and before Obama took office Russia threatened to install ballistic missiles in its Kaliningrad enclave bordering Poland and Lithuania if the project went ahead.
Moscow said it would welcome any revision of the plans.
U.S. Defense Secretary Robert Gates said Washington would now initially deploy Aegis ships equipped with missile interceptors and that negotiations were underway with Warsaw and Prague about deploying land-based interceptors later.
Polish Foreign Minister Radoslaw Sikorski said the United States would also go ahead with deployment of a Patriot battery on Polish soil and the missiles would be armed.
The Polish and Czech currencies were unmoved by Thursday's news about the shield. Public opinion, especially in the Czech Republic, has not been very supportive of the shield plans.
"I am glad the radar will not be here. First, we will not be dependent on the Americans, and it is good for Russia because it will not have to be worried," said Martin Entlich, 33, a shop assistant in a grocery store in Prague.
"BAD NEWS?"
Not all reaction in the region was so relaxed, however.
Former Czech Prime Minister Mirek Toplanek, whose government signed the missile defence deal last year, said Obama was showing a softer stance towards Moscow.
"This is bad news ... after 20 years of our path into Euro-Atlantic structures and our very active involvement there, the process is being halted," Toplanek said.
Poland and the Baltic republics, in particular, have been disturbed by what they see as Russian "neo-imperialism" in Moscow's dealings with ex-Soviet republics such as Georgia.
In an open letter to Obama in July, senior figures from the region including Vaclav Havel of the Czech Republic and Poland's Lech Walesa urged him not to be swayed by Russian objections in making his decision on the missile shield.
Many Poles feel Obama does not understand their sensitivities, often rooted in historical tragedy.
Polish officials noted the timing of Thursday's announcement. September 17 marks the 70th anniversary of the Soviet invasion of eastern Poland following a non-aggression pact between Moscow and Nazi Germany; an event long characterised by Poles as "a stab in the back".
But analysts say Poles, Czechs and others in the region need to take a more hard-headed approach to security issues.
"I think it is good the Obama administration has behaved so clearly ... We need a cold shower when it comes to national security," said Olaf Osica, a security analyst at Warsaw's Natolin European Centre.
"We are still a NATO member ... lots of things link us (with the United States), including our forces in Afghanistan ... Missile defence has nothing to do with Polish security."
Echoing that comment, Adam Jasser of the DemosEuropa think-tank said this was an opportunity to "reset" relations between central European capitals and Washington.
"In a sense, the end of the missile project may be a catalyst for reforging of ties (with the United States) along perhaps less romantic and emotional but more pragmatic and natural lines," he said. (Writing by Gareth Jones; editing by Philippa Fletcher)