The Organization for Security and Co-operation in Europe is meeting in Vienna Wednesday in the latest attempt to avert a major European security crisis as Russia masses troops on Ukraine’s border.

After two other meetings this week ended in an impasse, there is little optimism that a third one will reach a breakthrough, although analysts say it is still important to keep talking.

“It seems the risk of war in the OSCE area is now greater than ever before in the last 30 years,” lamented permanent council chairman Zbigniew Rau of Poland as he opened the meeting.

Europe faced “a particularly grave threat to peace,” he added, and must cleave to its key founding principles that states are equal and should not use military force or threats.

Russian officials have offered a bleak assessment of talks so far, with United States and NATO officials firmly rejecting its main demand for an end to NATO’s open door policy for new members.