Doubts about Boris Yeltsin's health produced a ripple of nervousness within Nato and the European Union, adding uncertainty to the West's faltering attempts to redefine its relationship with eastern Europe and Russia.
The Kremlin crisis also raised strong doubts in Brussels over whether Russia will be able to play a full role in peace talks aimed at finalising a settlement for the former Yugoslavia. Without the support of Russia for the US-led peace effort, the entire deal could be in jeopardy.
In recent days, the Nato alliance has been encouraging Mr Yeltsin to accept a formula for a Nato peace-enforcement force which could allow Russian forces to take part in monitoring ceasefire lines and curbing outbreaks of violence. Moscow has insisted it must play a role in the deployment, but has refused to place its forces under Nato command.
The latest formula envisages giving the Russian troops non-combat tasks. However, negotiations on the force will be severely set back if doubts intensify about Mr Yeltsin's future.
Under the Partnership for Peace plan, top Russian diplomats have access to Nato ambassadors in Brussels. However, many of the alliance's best- laid plans could still be wrecked should Russia enter a period of internal political turmoil.
Criticism from Moscow has already forced Nato to slow down its much-vaunted plans to expand eastward. A more nationalist Russian leader would almost certainly take a confrontational approach on this issue.
Although the crucial East-West conventional-arms control agreement, CFE, is now largely tied up, there are doubts over Moscow's willingness to enforce all its requirements. Should a less co-operative leader replace Mr Yeltsin, Nato could find itself opening up the CFE negotiations once more.
Uncertainty in Moscow also complicates the Brussels debate over any eastern expansion of the EU. Any doubts about stability in the Russian capital may encourage member states, already stalling at the complexity of the task, to take a more cautious approach.