Before Wednesday night, in the days when the Greens had core values and beliefs, the rerouting of the M3 motorway away from Tara was a bit of an issue for members of the party. Their abandonment of that principle was one of the more shameless surrenders made in the rush to government; the last thing they needed, particularly so early in their new existence, was a reminder of how blatantly their TDs had fled from previously held positions. But on Thursday night, as John Gormley weighed up his new cabinet position against the sell-outs needed to achieve it, RTE began reporting that Roche, in one of his last acts as minister, had approved the destruction of the monument, a decision which makes inevitable the building of the M3 through the TaraSkryne valley. (It also, incidentally, comes as terrific news to the several Fianna Failsupporting landowners in the area, who will benefit hugely from the trade, commerce and development that will accompany the motorway. Pure coincidence, of course. ) Roche implied that his decision was an act of courtesy to his successor, who turned out to be Gormley. To have left it to him would have been passing the buck, Roche said during possibly the softest political interview carried out on RTE all year, on Tom McGurk's radio show on Friday. It was the comment of a sleveen, as his decision the previous day had been the act of a sleeveen. But it did come with some value attached. It demonstrated what Fianna Fail really thinks of Green issues and of the Greens, who are in government purely to make up the numbers and to implement Fianna Fail policy on the environment, in so far as that exists.

Since it became clear that the Greens would be going into coalition, and that the programme for government was little more than a recycled version of Fianna Fail commitments, a genetically modified copy of its election manifesto, many people have wondered just what it was that the party's TDs expected to achieve by this "dance with the devil" (copyright Ciaran Cuffe, Green Party TD for Dun Laoghaire).

One oft-expressed opinion was that they were interested purely in "Mercs and perks", as the cliche has it. This seems unfair, if only because the two ministers involved seem to have eschewed the use of Mercs and the perks won't amount to much more than being regularly savaged by the opposition.

Rather, the decision to enter coalition with no significant concessions from Fianna Fail, and having abandoned several core principles, appears to have been based on a kind of missionary zeal, commonly found in people who believe they know how to save the world. Although Fianna Fail has remained to a great degree unchangeable, and its leader is the second dodgiest Taoiseach in history . . . blocked from the top position only by the singular venality of Charles Haughey . . . the Greens seem to believe they can succeed where Labour and the PDs failed in the past and civilise their new coalition partner. As Dick Roche proved on Thursday, that is not possible. FF will not be guided or influenced by the desires of its government partner, except where those desires coincide with Fianna Fail policy.

The problem with adopting this kind of missionary position with Fianna Fail, as Labour and the PDs have discovered in the past, is that you tend to get a terrible going over rather than a good seeing to. Labour lost 16 seats in the 1997 election after doing a deal with Fianna Fail in 1992; in the election just gone, the PDs went from eight to two seats. It's true that the PDs did very well in 2002 after five years of government with Fianna Fail but that was mainly because Michael McDowell made a specific promise to the electorate, when he climbed up the pole in Ranelagh, to act as a watchdog in government.

The Greens, with no interest in being watchdogs, are now in grave danger of going the way of the PDs. Try as they might to spin it, the programme for government offers nothing of any significance to supporters of Green issues. It is all vague aspiration, a bible of buts and maybes. As Pat Rabbitte pointed out in the Dail on Thursday, the programme is often a Green-free zone. "The word 'review' appears in the document 56 times, " he said, "the word 'examine' appears 23 times and the term 'consider' makes 14 appearances." Specifics are rare.

For that kind of waffle, the Greens abandoned not just their core beliefs but their voters as well. In no constituency in the country did Green voters show any interest in Fianna Fail, transferring to them in only about 9% of cases. In Dublin Central, for example, 1,077 of Patricia McKenna's transfers went to FG or Labour candidates while 179 went to Fianna Fail. In Galway West, 3,279 of Niall O Brolchain's votes went to Fine Gael and Labour while 408 went to Fianna Fail. After Dan Boyle . . . subsequently one of the Green government negotiators who were played for fools by Fianna Fail . . . was eliminated in Cork South Central, 5,197 of his transfers were hoovered up by Rainbow candidates while Fianna Fail won 619. All over Ireland, the pattern was the same.

Some of these voters voted for the Greens because they are interested in Green issues, and many will be appalled at how little that is specifically Green appeared in the programme for government.

Some of them voted for the Greens because they didn't want to see Fianna Fail in power and didn't quite believe Labour Party assurances that they wouldn't do a deal with Ahern. How stupid those people must feel now. And how angry. We will have to wait a few years to see if that anger lasts.