A week ago the talks produced some significant practical results.
For nearly a decade now talks have been held - on and off - about extending the rights of Macedonia's sizeable ethnic Albanian minority.
Following a month of daily clashes between ethnic Albanian gunmen and the Macedonian security forces in March, it has appeared in recent weeks that the previously often half-hearted negotiations would now turn into a more meaningful dialogue.
But the killing of eight members of the Macedonian security forces, leading to Monday's day of national mourning, has highlighted the difficulties of reaching an agreement between Macedonia's main ethnic communities
A week ago the talks produced some significant practical results.
The main Macedonian parties agreed to the ethnic Albanians' demand to postpone the census from May to October.
Always a controversial issue - with ethnic Albanians claiming that their numbers are consistently underestimated - the census is now even more of a political hot potato because several tens of thousands of ethnic Albanians fled Macedonia during the conflict, and their leaders want them to return before the head-count can go ahead.
The Albanians also received assurances that a separate Albanian-language television channel would be established by the state broadcaster in addition to the many private stations already operating in the country.
Several key issues have yet to be addressed in full at the talks.
Most importantly, ethnic Albanians want the constitution amended in such a way as to make Albanian Macedonia's second official language - and Macedonia defined as a state not just of its Macedonian majority but also of its Albanian minority.
Progress
In spite of this and other still outstanding issues, progress at the talks has been quite impressive. That is because international pressure and domestic circumstances have combined to lend an urgency to the talks.
On the domestic front, Macedonia's leaders have been eager to exploit the relative quiet of the past month to forge ahead with discussions - before a possible resumption in the fighting which might spiral out of control unless nipped in the bud.
The momentum for progress has also been strong on the international stage where both the European Union and the United States have weighed in to urge a speedy settlement.
And President Boris Trajkovski, who is scheduled to meet President Bush and secretary of State Colin Powell during his visit to Washington this week, was hoping to discuss the progress already made.
Talks in danger
But by the time he left events had taken a different turn.
"The talks in Washington will probably take a different direction now which means asking for strong support from the US administration in dealing with or stamping out the presence of terrorist groups in the Republic of Macedonia, which not only want to harm the political dialogue, but also this country's future and survival."
As Mr Trajkovski indicated, the danger now is that Saturday's killings - the worst incident since the fighting flared up at the end of February - could derail the talks.
This was quite possibly the intention of those who launched the attack - because any bloodshed tends to polarize Macedonia's ethnic communities.
Supporters of the talks are hoping that the peace process will not be slowed down, let alone torpedoed, though the ethnic Albanians - whose leaders condemned the attack - are likely to be angered by Macedonian state television's decision to suspend the Albanian-language news programme for its alleged backing of violence.
In Washington, President Trajkovski will be seeking reassurances of increased American support to combat the ethnic Albanian militants - both through bilateral aid and a tougher approach on the part of international peacekeepers to prevent infiltration from neighbouring Kosovo.