British cabinet ministers believe Mr Blair has come into his own during the Kosovo crisis, seeing his "just war" as a moral as well as military crusade. They see it as a foreign policy parallel to his belief in creating social justice at home, stemming from his Christian Socialist beliefs. At the same time, Mr Blair feels completely at home with Britain's armed service chiefs - unlike many of his Labour predecessors. He struck up a good relationship with the chiefs of staff while he was Opposition leader. "He sometimes gives the impression he would like to go on the bombing raids himself," quipped one minister.
For the past three months, Mr Blair has devoted most of his waking hours to Kosovo, to the surprise of Cabinet colleagues. At the same time, he had to juggle the fragile peace process in Northern Ireland and the already gruelling day-to-day grind of government.
At both home and abroad, Mr Blair can expect to reap a dividend from the peace settlement. He can argue that Nato's determination to stand firm produced a deal very much on its own terms and not those of President Milosevic. The agreement will enhance Mr Blair's reputation on the world stage, helping Britain to "punch above its weight" as the Foreign Office calls it.
Mr Blair will get the credit for stiffening Nato spines - including Bill Clinton's - when they threatened to "go wobbly". Mr Blair and Mr Clinton are back on good terms now, but there was a sticky patch when the US President told the Prime Minister to get a grip on aides he accused of highlighting Nato's differences by talking up the possible use of ground troops.
In the event, the 10-week air campaign worked without Nato troops going in.