Nato is due today to authorise the deployment of Patriot missile batteries to the Syrian border amid apprehension that the regime of President Bashar al-Assad may launch attacks using its stock of chemical weapons.
The alliance's Secretary-General, Anders Fogh Rasmussen, said he was confident that a ministerial meeting of member states in Brussels would agree to a request by Turkey to the deployment of the system, which could then take place "in a matter of weeks".
Mr Rasmussen insisted that the stationing of the missiles was "purely defensive and not an offensive" measure. However, the decision is likely to lead to charges that the West risks getting drawn further into the bloody 22-month civil war as well as polarising international relations over the conflict.
Russia, which has backed the Damascus regime, has criticised the prospect of the Patriots being deployed. Moscow's Foreign Minister Sergei Lavrov is arriving in Brussels today and is expected to reinforce his country's objections. Iran, another supporter of President Assad, has been highly critical of the move, accusing Nato of "going down the road of aggression".
During a visit to Turkey yesterday, the Russian President Vladimir Putin said of the Patriot deployment: "Creating additional capabilities on the border does not defuse the situation but on the contrary, exacerbates it. You know, as they say, if a gun is hung on the wall at the start of a play then at the end of the play it will definitely fire. Why should we need extra shooting at the border? We are urging restraint."
Mr Rasmussen, however, said that Nato had a duty to provide protection for Turkey, a member state. "We know the Syrian regime has missiles and it also has chemical weapons; this must be taken into consideration in making our decision," he said. "We are not saying that the regime will use chemical weapons, we have no information about that, but it is not something we can ignore either."
Mr Rasmussen said that the deployment was not a precursor to the establishment of a no-fly zone or other military action.
"We have no intention of becoming militarily involved in Syria, there are no such plans," he said. "We want to see a political solution to the crisis. But a request has been made by Turkey, a member, an assessment is being made [about the deployment]. I expect it will take place in a few weeks."