I have had plenty of critical words for the Ulster Unionist Party over the last number of years. Being in government, but yet not really in power, just didn’t make any sense. I never understood how its own party interests could be served as long as it was unable to distinguish itself from its competitors. More importantly, I never understood how the lack of genuine electoral choice or accountability served the interests of the people of Northern Ireland.

We have been in desperate need of an opposition at Stormont for some time. A government involving all of Northern Ireland’s main parties may have been necessary to successfully establish devolution in the short-term, but it has proven no way to successfully sustain it in the long-term. If our governing institutions are to survive, they must be credible. And for our system of government to be credible, there needs to be at least the possibility of the government itself changing. That’s a crucial test of a healthy democracy.

On the face of it, I must welcome the recommendation of Mike Nesbitt to withdraw his party from the Northern Ireland Executive. His intention to form an opposition is, in principle, positive. However, given the stalemate between governing parties over welfare reform, the disfunctional nature of Executive decision-making, and the UUP’s refusal to endorse the Executive’s own Budget, it is a decision that is, frankly, long overdue. Therefore, I can only welcome Mr Nesbitt’s announcement with a great deal of caution. Indeed, if his intention is simply to outflank the DUP and provoke its withdrawal from the Executive, then the people of Northern Ireland will be left with neither government nor opposition.

Mr Nesbitt and his colleagues have much to prove. As the dust settles, we will soon learn whether the UUP’s withdrawal represents genuine leadership or blatant opportunism. The decisive issue now facing the party is what type of opposition it plans to offer the people of Northern Ireland. Will it offer the kind of bold, yet responsible, leadership that has been missing from our stale politics, or will it offer more of the same, albeit without a ministerial portfolio? Will it offer a constructive voice and present a clear vision on how to fix our broken institutions, or will it fan the flames from the sidelines and provoke the other parties to move further to the extremes?

There is an unfortunate paradox here. Taking the decision to leave the Executive today has probably been easier for the UUP now than it would have been at any other time over the last four years. The political climate is so toxic that it will take little to convince internal sceptics of the merits of its decision. At the same time, however, it is precisely because the political climate is so fragile that it will require significantly more effort for the UUP to emerge as a voice of constructive leadership from the opposition benches. Instead, it risks falling into the trap of making a tense situation even worse.

If Mr Nesbitt genuinely wants to make opposition work for the people of Northern Ireland, he should pay close attention to the words of President Dwight D. Eisenhower: “You do not lead by hitting people over the head – that’s assault, not leadership.” If the UUP’s move represents anything beyond short-term tactical opportunism, Mr Nesbitt must prove – and prove urgently – that he has a plan that isn’t merely about blaming his opponents. Such a plan will require tactful manoeuvring, not a sledgehammer.

Northern Ireland is in a political mess. We’re used to that, which makes the current mess all the more dangerous. Our public finances are unsustainable, parts of our society remain deeply divided, and paramilitary groups, both republican and loyalist, are still engaged in criminal activity. The challenge for the UUP is to make its withdrawal from the Executive count for the better. It must resist the temptation to mount an assault on our already fragile political institutions, and instead demonstrate responsible leadership. It must resist the urge to trigger the collapse of our governing institutions, and instead offer a realistic vision of how it would govern this place differently.

That’s much more easily said than done. For an opposition party, however, saying things is actually much more important than doing things. That’s why Mr Nesbitt must choose his next words very carefully. If in doubt, Mike, listen to Ike.