It sounds like a simple brief. Write about the Dick Spring I knew. Except that I never knew him. I admired him, trusted him, worked well with him, sympathised with him, laughed with him, observed him. But I never knew him.

Not personally. Not in the unguarded risk-taking way deep friendships happen. But then, I suspect few of those around the cabinet table at the time I worked with him ever got to know him personally. He was a man on a permanent mission, who could not let down his guard for a moment, whose every communication was threaded with caution.

That suited the work the two of us shared when he was Tanaiste and minister for foreign affairs and I was minister for justice. We attended all Anglo-Irish meetings and worked together very closely in what were often tough negotiations, dealing with the same subject.

For me it was a security issue, while for Spring it was a political one, although the two were inextricably inter-related. A strong mutual trust built up, allowing us to think in parallel under pressure.

And yet I felt I should not ask him about the back pain that dogged his life, even on the days when a stoop came into his gait and his face froze in denial of the discomfort. To express sympathy would have felt like an invasion, because he seemed determined not to allow anybody to get close to him.

Which is not to suggest that he was anything other than courteous, or that he could not manage small talk. On our regular visits to London, we would have an official car to get from the airport to the meeting place, whether it was Downing Street or Whitehall.

Inside the car: Dick Spring, the ambassador, the driver and myself talking about a million different things that had nothing to do with politics - once, I remember, an exchange of memories of boarding school. He could demonstrate a lively sense of humour, albeit very rarely.

Every now and again, he would talk about characters within the Labour Party. Sometimes I would push him into guessing who on the Fianna Fail side was likely to approve of a particular move and who was likely to disapprove. He was often surprised by the actual out turn, partly because he tended to associate youth with liberalism and age with conservatism. Within Fianna Fail, that isn't always the case.

Once the humorous interlude was over, the drawbridge was drawn back up and the moat filled to discourage or drown invaders. Just as you felt you couldn't sympathise with him, you also couldn't praise him, lest he assume the praise was flattery with malicious intent.

I could never imagine myself telling him I admired him greatly, as the man who had taken on a Labour Party with two very different and opposed wings, over-influenced by the trades unions. He did a Tony Blair before Britain's New Labour was ever heard of, driving an agenda within the party that brought them into the modern age and took away a lot of the outside influences.

Not only did he mitigate external influences, he also, when the time came to go into government, identified the members of his parliamentary party most likely to get itchy feet and brought them inside the tent. On the front and second rows, the most potentially disruptive influences were positive and contented.

Not all of them were succinct, however, and the convoluted communication favoured by one of them was less irritating to the rest of us because of the fun of watching Spring almost physically controlling his rage. Down would go the fountain pen, up would come the hands, and the party leader would bury his face in them.

Moments of shared sympathy notwithstanding, in retrospect it is clear that it was a major mistake for Spring to go into government with Albert Reynolds and Fianna Fail in 1994. Not least because he underestimated the impact on himself and others of media comment.

Before that government was formed, everybody was talking about a rainbow. That's what people wanted. It was the preferred option of newspapers, which had urged people to vote for that possibility. The overwhelming likelihood, at the time, was that Fianna Fail would be going into opposition.

Many commentators and supporters never forgave him for doing the opposite to what they had wanted. The media punished him. That punishment undoubtedly contributed to the pattern Sean Duignan observed and recorded in his book, that when Dick Spring wasn't being touchy, Fergus Finlay was being touchy for him.

In a case of `he who lives by the sword, dies by the sword', both men invested great energy and thought in influencing media, and were disproportionately confounded by negative coverage. This, in turn, tended to lead them into conspiracy theories and all-pervasive suspicion.

That combination is bad enough on its own, but was complicated by their self-righteous assumption that any suspicion was probably justified because nobody in Fianna Fail could be as clean/virtuous as people in the Labour Party.

That said, Fianna Fail and Labour, for the most part, worked very well together and should still be the government of the day. As, indeed, they might be if the key relationship between the two leaders had been widened to include at least one minister on either side.

Genuine misunderstandings can happen between two people, but are much less likely to happen if there are two others present, even if only included ostensibly as note-takers. The destruction of that government boiled down to a direct conflict between the two leaders.

Those of us on both sides tried to intervene to put things back on track, but structural formality had replaced the mutual trust I, for example, would have had with Spring and other colleagues would have had with their Labour counterparts, and the end result was disaster.

When Spring found out that I had offered my resignation to the Taoiseach, he ensured I got the message: that's not what is wanted. I appreciated that. But later, when every phrase became a matter of mistrust and contradiction, he became a man made inflexible by the need to be right, and to be righteous.

The great tragedy of politics is that the traits and relationships which ensure success at the outset are precisely those which unravel so much at the end. Leaders should always relinquish their role long before ideas run out and drudgery sets in.

A fixed term gives deadlines to every programme and plan. It generates priorities. It creates a sense of urgency, excitement and challenge. In my view, the natural fixed term for party leadership is 10 years. Dick Spring might have chosen a happier departure date had he not waited until circumstances wrote finis to his leadership.

The departure date apart, this is a good week for Spring, with a generally positive assessment of his contribution, particularly to the Labour Party. It is the beginning of a retirement from the leadership which can only be enjoyable. It will not be devoid of pressure, but there will be nothing to compare with the pressures of the last few years.