Yet both men's preferred solutions, more peace conferences and "constructive negotiations" involving the Russians, seem no more likely to bring about peace than the failed talks at Rambouillet. Another critic of the war, John Pilger, has made the incredible claim that the Serbs have shot down nearly 40 Nato planes, a fact which has supposedly been covered up because so many journalists are uncritical supporters of the alliance.
His assertion is undermined not just by an absence of proof but the uncharacteristic reticence of the Serbs, who have failed to drag chunks of broken fuselage in triumph through the streets of Belgrade. I am a fan of Mr Pilger, so I do not make this point with any pleasure. But it is undeniable that the left is having a bad war, with some sections of it making dodgy claims and degenerating into gleeful slanging matches.
According to Mr Ali, supporters of the bombing include "the editor of the Sun and his admirers on the Guardian and the Observer". This is grotesquely unfair to journalists on those broadsheets, who are quite capable of deciding what they think about Yugoslavia without reference to the mindless jingoism of David Yelland. (It was, after all, the Guardian which gave Mr Pilger space to denounce the bombing.) What is at work here is a mixture of crude anti-Americanism and a mentality shaped - perhaps even ossified - by the Vietnam war.
I have been struck by the extent to which the disagreement is generational, with men over the age of 50 - veterans of the 1960s demonstrations against American involvement in South-east Asia - launching splenetic attacks on younger colleagues who favour armed intervention in the Balkans. This was confirmed last week, when I ran into a left-wing journalist who volunteered that "this war has really got my juices going". He added enthusiastically: "I hate people who support this war." When I said I was in favour of sending ground troops into Kosovo, he stared at me in silence. Does he hate me as a "warmonger"? That is the logical conclusion of his declaration. Yet it has always seemed to me that there are at least three honourable positions on the current conflict.
One is outright opposition, as expressed by the editorial columns of this newspaper. Another is reluctant support for the air war, although it has been considerably eroded by Nato's widening of its list of targets in a way that puts civilians at risk. The third, which I have consistently argued, is that intervention should have been undertaken earlier, on the ground as well as from the air.
At the beginning of the war, at a dinner organised by the left-wing paper Tribune, some of us debated these issues with Michael Foot, who supports the Nato intervention, and the comedian Mark Thomas. The dozen people sitting round the table held very different views, which were expressed forcefully, but without rancour. When civilians are being bombed and driven from their homes into refugee camps, there is something peculiarly distasteful about conducting arguments at a level of personal abuse. But then there have always been people on the left who positively welcome disagreements as the excuse for a display of middle-aged machismo.
WHO TO VOTE FOR in the European elections on 10 June? A helpful missive from Tony Blair drops through my letterbox, introducing Labour's team. "Labour is working for you in Europe," Robert Evans announces controversially, while Shaun Spiers is even more daring: "We're making Europe work for you." Yes, but what about, um, policies? I turn to the brief biographies and discover that Mr Spiers has twice been a judge of the Champion Beer of Britain competition. Richard Balfe likes walking. Carole Tongue is a West Ham fan. Pauline Green likes Star Trek and Dusty Springfield records. With such an array of Renaissance men and women on the Labour slate, it would be churlish to ask what they think about the euro or the war.