A minor hiccup, or a sign of a serious rift in relations?

These were the questions raised by this weekend's decision by the US to block the flights of Russian troops to Kosovo.

The Americans accused the Russians of flouting the terms of the agreement on the deployment of Russian troops reached at Helsinki by senior US and Russian defence officials.

They said that the Russians wanted to get their troops on the ground before finalising arrangements, instead of working out the details before any more troops are sent to the area.

Tense relations

Russian troops raced to reach Kosovo first

But despite the apparently successful outcome of the talks in Moscow, this episode has illustrated that relations between Russia and Nato are still tense.

The relationship was hit hard by Nato's bombing campaign against Yugoslavia, which was strongly opposed by Russia.

As a way of striking back after a peace deal was reached in Kosovo, the Russians were the first to move their troops into the territory, seizing Pristina airport and, for a time, refusing to allow Nato forces to pass.

Moscow put forward tough demands that it be allowed to send 10,000 troops to Kosovo, and that it be granted its own sector of responsibility.

Ethnic enclave

Given Russia's links with the Serbs, Nato commanders feared that this would effectively create a Serb enclave within Kosovo, which could merely prolong ethnic tensions in the region.

Ultimately, at the talks in Helsinki, Russia and Nato reached a compromise whereby just over 3,500 Russian troops would be sent to Kosovo, to be deployed in sectors controlled by the Americans, the French and the Germans.

Even though this latest disagreement seems to have been settled, a question mark still stands over just how coordinated Russia's actions are.

Certainly, it looks likely that the decision to send the troops to Pristina airport over three weeks ago was taken not in Moscow, but by the military commanders on the ground.

Pulling strings

And it is highly possible that it was the military that was trying to pull the strings this time, in spite of the agreement reached at the highest level, or anything else which the Kremlin might say.

For the Russian military leadership, the involvement of their troops in Kosovo gives them an opportunity to try to regain some standing on the world stage.

They have seen a once proud army humiliated in Afghanistan and Chechnya, and accused of becoming a political pawn in Moscow's internal struggles in 1991 and 1993.