The words police and politics are from the same Greek stem.

So it is unsurprising that the two will become increasingly entwined in the run-up to the General Election on both sides of the Border.

In fact, policing and police reform are increasingly becoming party-political issues across Europe as nations wrestle with ever-more-complex challenges from criminality and shrinking budgets.

I wrote the independent review that initiated the path to a single force in Scotland and I am continue to follow the process with interest.

However, after working internationally for the last five years, I think the polemics about Police Scotland look very different in the light of what has been happening overseas and south of the Border.

Like Scotland, our neighbours in Scandinavia and the Netherlands have all instituted police reform programmes.

But none has made the progress we have and many police leaders and politicians have shared their admiration and envy for the political and operational leadership shown in Scotland.

This is amplified in England and Wales, where the damp squib of achieving "localism" and accountability through Police and Crime Commissioners (PCCs) has done little but pile cost and complexity on an already fragmented and wildly unequal map of policing structures.

The President of the Association of Chief Police Officers, several chief constables and even PCCs, have openly argued for emulating Scotland.

This, however, has met implacable resistance from a Home Office trotting out half-hearted defences of a system that has won little but record-breaking apathy from local electorates.

Voluntary collaboration between forces in England and Wales as a way of securing economies of scale has proved illusory.

Major programmes and partnerships - for instance sharing specialist units or computer system purchases - have been started only to be abandoned under the weight of purblind parochialism and a focus on short-term electoral cycles.

Meanwhile police numbers fall, budgets are cut and the patchwork quilt of the map of forces highlights the inflexibility inherent in small organisations with high costs.

Pity the poor Bedfordshire and Lincolnshire forces which, according to HM Inspectorate of Constabulary, are on the cusp of becoming non-viable.

The creation of Police Scotland was the most profound reform since the advent of recognisably modern policing in Glasgow more than 200 years ago. It is remarkable that anyone could think it would be without difficulty, disruption and, for many members of the former police forces, considerable pain.

That so much progress has been made in such short time is astonishing. A queue of distinguished witnesses from across the globe would agree.

By any common measure of performance, the uninterrupted reduction in crime, particularly Scotland's bane of violent crime, is compelling evidence of the professionalism, commitment and vocation of all in leading and adapting to fundamental change.

Police reform created a new landscape for governance and accountability.

Police Scotland sits at the centre of a complex web of bodies that takes an interest in and exercise powers over it. They include Parliament, the Scottish Government, the Scottish Police Authority, Audit Scotland, the Police Investigations & Review Commissioner, HM Inspectorate, the Office of Surveillance Commissioners and local policing committees.

The fact that much of the recent debate on stop search and armed policing has taken place at Holyrood shows that the centralising of police command has been balanced by a centralising of its accountability mechanisms.

That this becomes national news rightly reflects that a national service is being asked to account for its methods at the heart of national democratic authority.

This is realpolitik: an example of how Scotland's system of governance is working in practice.

After 30 years in policing I do not have a Pollyanna world view.

But I am confident that the many people internationally who admire Scotland's achievements, such as the world-leading Crime Campus at Gartcosh, are right.

Police reform continues to be a work in progress. However, in addressing real challenges in policing practice at home, we should not forget that we have much to offer in supporting reform and co-operation in policing across the world.

Paddy Tomkins is Chief Inspector of Constabulary for Scotland.