As the US Secretary of Defence, Mr William Cohen, insists that there are no plans for ground forces to invade Kosovo and that the NATO air strikes will force President Slobodan Milosevic to accept its conditions for a settlement, Newsweek reports that the Joint Chiefs of Staff believe ground troops will be necessary to achieve the political objectives.
The magazine says the letter of the Joint Chiefs to Mr Cohen, allegedly written several weeks ago, could be just a matter of the military "covering its collective backside", but added that "there is a growing sense in the military that time is running out."
But the White House, State Department and the Pentagon official spokesman all have been sticking firmly to the line that the air strikes will prevail over time and that, as President Clinton has said, there is "no intention" to send ground troops into Kosovo before President Milosevic has agreed to a settlement involving the withdrawal of his Serb forces from the Yugoslav province.
The Chairman of the Joint Chiefs of Staff, Gen Hugh Shelton, said yesterday: "Right now we are carrying out a very effective air campaign, not only against the strategic targets, those up around Belgrade, but also against fielded forces down in Kosovo."
The US Secretary of State, Ms Madeleine Albright, and the British Foreign Secretary, Mr Robin Cook, in a jointly written article in the Washington Post last Sunday, headed "Our Campaign is Working", said that continuing the NATO air strikes "is still the right thing to do".
Mr Cook is expected in Washington later this week for talks on the progress of the NATO campaign. The London Sunday Tele- graph has reported that he is coming to Washington "to stiffen Western resolve in the war against Serbia amid growing British military frustration over US reluctance to commit ground troops."
However, at the NATO summit in Washington three weeks ago, Mr Cook strongly rejected media reports of strain between Britain and the US over the use of ground troops and expressed confidence in the air campaign.
On the CBS Face the Nation programme on Sunday, Mr Cohen said, "There is no consensus within the alliance for a ground force."
The Washington Post reported yesterday that the Pentagon is mainly focused on the size and composition of the ground troops needed for escorting the Kosovan refugees back to their homes once the fighting has stopped. It is now estimated this peace-keeping operation would require double the 28,000 soldiers originally planned.
A civil force of 1,000 police professionals or more to accompany the troops is also planned. They would be charged with training several thousand ethnic Albanians to make up a new local police force.
It has not been decided who will set up the provisional government or civil administration in Kosovo - the UN or the 55-nation Organisation for Security and Co-operation in Europe or perhaps some new entity, the Post reports.
No hairline cracks were showing in the unity of the Allies when Mr Cook spoke to a press briefing in Brussels yesterday.
"The resolve of the alliance is greater now than it was in the beginning," he said.
NATO commanders have gone on the record with a letter insisting the success of the campaign rests on a ground invasion of Kosovo but Mr Cook ruled out any immediate plans to send in Allied ground forces until Mr Milosevic withdraws his troops.
He acknowledged, however, that Mr Milosevic's consent was not necessary for an international force to enter Kosovo and that he and the NATO Secretary General, Mr Javier Solana, had discussed the eventual form the ground force would take and what its tasks would be.
Describing some of the documented cases of refugees used as human shields, he said, "Five hundred Kosovan men were used as human shields during fighting against the KLA. One was forced to strip naked and lie in a field for two hours while the Serb artillery behind shelled the KLA in front of him."
Gen Walter Jertz reported only a "small number" of Serb armour, military vehicles and artillery positions were struck on Sunday. But by Thursday, when the weather is expected to clear, the attacks will increase again in intensity. Rumours of a split between Britain and the US over the direction of the NATO campaign were denied in London as the diplomatic effort to reach a peace deal in Yugoslavia quickened yesterday when European Foreign Ministers met in Brussels.
But as the diplomacy continued, the emphasis in London appeared to harden around the question of when ground troops would go in to Kosovo, not if. "At some point troops will have to go in," Downing Street said.