NATO's decision on Thursday not to ask Macedonia to join the alliance raised fears that the former Yugoslav republic could be destabilised and nationalist and anti-Western feeling could be bolstered in the Balkans.
NATO leaders at a summit in Bucharest invited Albania and Croatia to join the 26-nation Western defence alliance, but did not do the same for Macedonia because of the threat of a veto by Greece in a row over the country's name.
Macedonia, which broke from Yugoslavia in 1991, has the same name as Greece's most northerly province. Athens says Skopje must use a compound name such as "New" or "Upper" Macedonia.
Macedonian Foreign Minister Antonio Milososki said last week that if NATO membership was blocked, Macedonia would probably pull out of U.N.-sponsored talks with Athens.
That could undermine Macedonia's European Union membership bid because Greece can also veto that.
"Acceptance into NATO has been a hugely important symbolic move for all ex-communist countries. This leaves Macedonia without a foothold in what they perceive to be the 'civilised world'," said a strategic analyst with a leading Western think tank who spoke on condition of anonymity.
The Balkans region is already facing increased tension following Kosovo's declaration of independence from Serbia on Feb. 17.
Macedonia went to the brink of civil war in 2001 between the Slav Macedonian majority and an Albanian minority before an accord brokered by the EU and NATO pulled it back. "This (NATO decision) will have negative consequences. The Macedonian government will face pressure from inside and outside," Albanian political analyst Mentor Nazarko said of Nato's decision.
Nazarko said NATO's decision would make Macedonia "vulnerable" to regional powers such as Greece and Serbia who he said wanted Macedonia weakened.
SETBACK FOR PRO-WESTERN GROUPS
Macedonia's Albanians, a quarter of its 2 million people, back a compromise with Greece for the sake of NATO and the EU.
They say progress to the West will make them equal partners in a multiethnic society, and help the economy. Most feel uneasy about talk of a glorious ancient history that excludes them.
Aziz Pollozhani, a senior official in Macedonia's largest Albanian party, DUI, said the government had in effect failed at the NATO summit Bucharest .
"It wasn't able to build an appropriate climate, on the contrary made moves seen by Greece as provocative," he said.
Slobodan Casule, a former Macedonian foreign minister, said the delay could create "ethnic tensions and an internal crisis".
He noted that there had been setbacks for pro-Western groups in other parts of the Balkans.
"This will turn into a clear defeat of pro-NATO and pro-EU forces in Macedonia, Serbia, Bosnia and elsewhere in the Balkans," Casule said. "It will block reforms and postpone indefinitely the negotiations on Macedonia's EU membership."
Former Prime Minister Vlado Buckovski called for calm, not provocative actions.
"Macedonia should not complicate the situation even more with jerky reactions, like withdrawing from the U.N. talks," he told Reuters.
"We should soberly analyse what our next steps should be. We should send a clear signal we're still ready for negotiations so we can finally receive an invitation."
Political analysts said NATO's decision could play into the hands of Macedonian nationalists, enabling them to say compromises with the Albanian minority had served no purpose.
The analysts said the decision could also strengthen nationalists in Serbia, which holds a parliamentary election next month, and anti-Western parties in Serbia who like to play up their friendly ties with Greece.
"They will start banging the drum to exploit this ahead of the May election, saying Greece can help Serbia over (breakaway Albanian-majority) Kosovo," the analyst said.