I realised David Trimble and I would get on fine when we met for the first time. Over lunch just off Whitehall in the early 1990s, I asked Trimble, in those days the embodiment of a hardline backbench Ulster Unionist MP, if he ever spent time in the Irish Republic. With a grin, he replied that he had just recently been in Dublin for a performance of Leoš Janáček’s Kát’a Kabanová, a work he greatly admired. We spent the rest of the lunch talking about opera as well as politics. It was clear that this was a unionist politician who was worth knowing. And so it proved over many years, in conversations of every kind. Trimble, who died this week, was smart, approachable, sometimes sharp, but above all an immensely practical politician. He came from a relatively liberal unionist family background in County Down, but he always knew he had to carry his ardently loyalist base in his Upper Bann constituency along any new path that he advocated or that events required. He was one of those politicians who think around corners, not in straight lines, the best sort. Politics for Trimble was certainly about defending strong unionist interests. That thread unites the implacable role he played in the Drumcree confrontations of 1995 with his more supple approach towards talking to republicans in the years that followed, as well as his bleak and mistaken support for Brexit. But those politics were also about adjusting to and helping to shape change in Northern Ireland. During the key decade starting in 1995, when he became UUP leader, until 2005, when his party was crushed by Ian Paisley’s DUP, he often proved pretty good at it, above all when he delivered a unionist majority for the power-sharing Good Friday agreement that he signed in 1998. A quarter of a century on, it is easy to take for granted what Trimble, along with many others, achieved back then. It is extremely important not to do that. The Northern Ireland in which Trimble lived the first half of his adult life was the grimmest, most unjust and violent place in western Europe. Money, hope and trust were in very short supply. The Northern Ireland that Trimble helped create after 1998 may indeed be very far from perfect, but economically, politically and culturally it is another world. In the words of his biographer Dean Godson this week, this is why Trimble mattered. Trimble was never the stereotypical parochial Ulster politician and he was always interested in the bigger picture. He once berated Steve Bell for always depicting him in a bowler hat, an item of Orange iconography he indignantly denied ever possessing. With his wide cultural hinterland, he thought of himself, and Northern Ireland unionism, as players on a British and sometimes even an international stage. Although borders loomed extremely large in his political career, he proved in the end to have surprisingly few mental barriers of his own. This is partly why, as a unionist in practice as well as in theory, when he lost his Westminster seat, he gravitated more towards Britain, becoming a Conservative peer and spending some of his downtime piloting his narrowboat through the canals of England. When the Tory conference was in Birmingham, the Trimbles would moor in the Gas Street basin. He sometimes moored right by the Guardian’s offices in London, and the last time we met was when I bumped into David and his wife, Daphne, drinking white wine in a canalside garden there. Advertisement Yet if Trimble mattered – which he did – his way of doing politics was the key. And that approach should not be allowed to perish with him. This brings us to the great irony of his later career. Just when Trimble, the Ulster Unionist with the hinterland who thought around corners, decided to become a Tory to emphasise, in part, his break with the fundamentalist and zero-sum politics of Northern Ireland, so, at the same time, the Tory party made the opposite break with its own more pragmatic past and began to embrace a fundamentalism of its own, making it more than ever like a British version of the DUP. So, when Rishi Sunak and Liz Truss began their first debate on Monday by each praising Trimble as a political giant, do not be taken in. Neither Sunak nor Truss is a Tory in the sense that Trimble understood it. Neither of them shows any inkling of being interested in Northern Ireland, in the mishandling of the Brexit process there, or the wider dangers that threaten the UK’s union. These are not the only subjects that have been almost totally ignored in the leadership race – not least by most of the press, which was never even remotely interested in Northern Ireland anyway – but they are certainly among the most important. There was much to disagree with in Trimble’s politics. He got a lot of things wrong, though he got the one big thing right. But when Trimble adopted a hard political line, or behaved unreasonably, it was almost invariably as a means to an eventual compromise end, not as an end in itself. Particularly in Truss’s case, and increasingly in Sunak’s, the hardline attitude is all that there is. Truss does not want to override the Northern Ireland protocol because she cares about Northern Ireland’s future but because she does not. Whatever you may think about him, you could never say that about David Trimble. Martin Kettle is a Guardian associate editor and columnist