But the EU and Nato are both facing severe problems after the deaths in Sarajevo, which come at the beginning of a crucial week. The latest attack stretches the credibility of the alliance to breaking point, puts new pressure on transatlantic relations and is likely to undercut public support for Europe's strategy.
Nato aircraft in Italy and at other airbases throughout Europe are ready to launch attacks around Sarajevo following alliance decisions made in Brussels last August.
The political questions, however, loom larger than military ones. The agreement of all 16 Nato countries would be required before strikes could be launched, as would the agreement of the UN Secretary-General. The US originally pressed last August for the threat of air power to be used in defence of Sarajevo, with resistance from Britain and France.
The US has become more reluctant to push the issue. 'President Clinton has already stated that we would not permit the strangulation of Sarajevo,' William Perry, the new US Defense Secretary, said yesterday. 'If the action which is being described today would be seen to be strangulation, and we cannot prevent that, we would definitely consider stronger action, including air strikes,' he said.
Although all EU members had come closer to accepting the neccessity of limited action to open Tuzla airport and allow the rotation of troops in Srebrenica, diplomats stress this is a very different matter from punitive action around Sarajevo.
Intense pressure is building up, however, over the lack of results that the Western strategy has shown, while civilian casualties continue to mount. Alliance sources say that there is a danger that without action, threats become counterproductive and that alliance credibility - accumulated over 40 years - is exhausted. After the threat of air strikes was first raised, there was a measurable effect, they say: shelling was reduced, supplies increased and power supplies returned. After the threat was reiterated in January at the Nato summit, no similiar effect was recorded.
'The situation now is at least as bad as last August,' one alliance diplomat said last week, 'but nothing is happening.'