Except for a short blip in the mid-1990s, this has been the Nationalist Party's quarter century. All that we see around us is a reflection of that party's performance in government. How should we judge it?

The paramount duty of any government is to ensure the safety and security of its people, and that their liberty and economic well-being are assured. This imperative lay at the heart of Malta's momentous step in 2004 to join the EU – the second most important decision after Independence forty years earlier. This was the pivotal event of the last twenty-five years, and it is to the Nationalist Party's eternal credit that they took it.

Throughout the last quarter century, three interlocking objectives have had to be met in order for Malta to thrive.

First, the maintenance of high and stable levels of economic growth and employment. To prosper, Malta had to be competitive and entrepreneurial, able to weather the storms that beset a micro-state like ours.

Secondly, there had to be social progress that recognised the needs of everyone.

Thirdly, there needed to be effective protection of the environment and the built heritage. This meant government had to act to protect things that people valued, such as the natural landscape and historic monuments and sites.

It is against these broad criteria that the quarter century should be judged.

Malta's economy has been transformed. It is an economy which has grown by leaps and bounds judged by all the measures of infrastructural and social improvements, personal indulgence and consumerism. Malta has experienced real economic growth in the last quarter century which has seen national gross domestic product more than doubled in the period, with commensurately large improvements in national income per head.

Malta's liberal economy remains extremely dependent on foreign trade and is vulnerable to all the vicissitudes that characterise such an economy, relying substantially on imports for its industrial supplies and consumer goods and on exports of goods and services for income. If goods and services are not competitive, the economy stumbles. Competitiveness continues to plague Malta's progress.

Moreover, our proclivity to consume has increased significantly in the last twenty-five years and shows little sign of abating. The thousands of cars on our roads, air-conditioning in the majority of homes, colour televisions, modern household goods, home ownership (including second homes), personal computers, mobile phones, holidays taken abroad and others - all these largely unheard of except for the privileged few before 1987 - are the mark of the increased prosperity of the majority (not all) of Maltese citizens.

Household and government consumption has increased substantially, while savings as a proportion of disposable income have declined significantly. Government debt, which was virtually non-existent in 1987, has increased to about 5 billion euros, a massive 90% of GDP. Excessive consumption threatens the economy.

Over the last quarter century, government investment in essential infrastructure projects, which had previously been neglected to Malta's detriment, has expanded hugely. The international airport, the new hospital, the new power station at Delimara, modern telecommunications, the internet, the expanded free-port and many others have all contributed to making Malta a modern European state. The financial mill-stone that was the Malta Dockyards has finally been shed. Air Malta is showing tentative signs of revival.

Infrastructure investment has made Malta an attractive destination for foreign direct investment. With the exception of the road network, which despite recent improvements thanks to EU funding still lags behind, the improvements to Malta's infrastructure of the last twenty-five years have made a vital contribution to its economy. More remains to be done, especially in the crucial fields of water and energy resources.

Institutional development has been mixed. The civil service, which had become a spent and demoralised force by 1987, and the Malta Police Force – similarly broken and ineffective – have been hugely improved. More remains to be done, especially with the latter. The Armed Forces of Malta have been modernised and continue to be well led. The judiciary, the prison and the exercise of the rule of law, however, still exercise growing concern.

In the social field, the Nationalist quarter century has witnessed massive investment in education (with more graduates than ever each year), medical services and welfare benefits. Malta can rightly boast that in terms of personal income, education, health and the safety-net provided by social services, it ranks on a world basis in the top 30% of nations enjoying a high standard of living. Abject poverty is notable by its absence, although relative poverty (those living officially below the poverty line) – especially among pensioners and single parents – has been increasing in recent years.

But an ageing population and a smaller work-force to sustain it mean increasing strains on all aspects of Malta's welfare system. In sustainability terms, the rapidly growing welfare gap carries with it the seeds of its own destruction – an extremely worrying challenge which no Nationalist administration has yet properly addressed.

The bottom line is that although the Nationalist quarter century has been largely successful in delivering social cohesion and stability, these factors alone cannot be enough to sustain the country's economic growth at the levels needed to maintain Malta's generous welfare system. Successive administrations have bequeathed a legacy of welfare schemes and free public services that have distorted incentives and encouraged waste. Most importantly, they are largely unsustainable.

As to the third leg of Malta's sustainability platform, the Nationalist quarter century's environmental policies have been a blot on their record. Until very recently when the last administration woke up to the depredations of the “environmental deficit,” Malta had opted for economic growth combined with social improvements, at the cost, invariably, of its environmental quality of life. The penalty for economic growth has been heavy.

The consequences of environmental degradation have been economically short-sighted since they affect the productive potential of an economy so highly dependent on tourism. The Nationalist quarter century's stewardship, judged against the criterion of passing on the island in a state at least as good as that inherited from the previous generation – which itself was grossly uncaring of the environment – has been lamentable. Malta's accession to the EU has helped to instil much-needed discipline in the government's approach to the environment and structural funding has helped improve waste-management. But more, much more, still remains outstanding, and so much of Malta's natural landscape has been lost.

Overall, the Nationalist quarter century has been a transformational period in Malta's economic, social and environmental development. While not everything has been for the best, there can be no doubt that,  together, the benefits to Maltese citizens have been outstanding. What in 1987 was a country only slowly emerging from “developing nation” status is today a modern nation state, comfortable in its role as a member of the European Union and confident of its position as a liberal, European parliamentary democracy.

More remains to be done. There are formidable challenges ahead economically, socially and environmentally. But Malta starts the next quarter century from a solid platform unknown anywhere else in the Mediterranean Basin. The Nationalist quarter century has, on balance, been a considerable force for good in Malta.