Professor of Law at the University of Waikato, Alexander Gillespie, dissects the UN agreement he claims is making Europe go mad.

OPINION: By definition, an international migrant is a person who is living in a country other than his or her country of birth.

In New Zealand, originally we were all migrants, arriving from somewhere else. Subsequent arrivals have always been complicated. From the Treaty of Waitangi in the 19th century onwards, our country has always struggled with such matters. These struggles have intensified as debates about migration have split between invited and legal migrants, illegal migrants (typically 'overstayers'), and refugees.

It is only in the last 30 years that the country has truly started to develop more humane and non-discriminatory approaches to such matters.

Despite this progress, such topics, often muddied together, remain popular political footballs to bring out at election time.Even debates about whether we should repatriate our own citizens, who are or have been prisoners in other countries, bedevil national debates.

The intensity over the migration question in New Zealand has grown as has the number of migrants, according to the United Nations. Thus, what were 679,000 migrants in the year 2000 at 17.6 percent of the population has expanded to some 1,067,000 in 2017 to now be 22.7 percent of the population.

The New Zealand figures are a small subset of a much larger pattern. Worldwide, the number of international migrants reached 258 million in 2017, up from 173 million in 2000. These numbers are supplemented by 25.4 million refugees. As world population expands from 7.4 billion today to 9.7 by 2050, the expectation is that the numbers will expand.

It is these vast waves of humanity that lead to the international community to call for the development of two compacts, one on refugees and one on migrants. The contextual difference between the two is that where there is a settled and coherent international law on refugees, on migrants there is a gap.

For migrants, there is only a collection of ad-hoc principles of differing weights taken from a multitude of obligations from, amongst others, international laws and policies on human rights and labour law.

The new Global Compact for Safe, Orderly and Regular Migration attempts to advance this area in a soft way. That is, the Global Compact is not a treaty. It is not a legally binding document. It, like hundreds of comparable documents in international law, is nothing more than a collection of goals and principles made visible and coherent which should be softly persuasive to governments as ideals they should aspire towards, not those which must be blindly and obediently followed.

The Global Compact does not take any radical new steps. Fundamentally, as there is no right to migration in international law, the Global Compact does not try to create one. Rather, it underlines the importance of sovereignty in this area, reaffirming "the sovereign right of States to determine their national migration policy and their prerogative to govern migration within their jurisdiction, in conformity with international law including the right of each government to determine their legislative and policy measures for the implementation of the Global Compact, taking into account different national realities, policies, priorities and requirements for entry, residence and work".

This right of each government was also underlined in the section on migration pathways where although it is hoped that such pathways will be 'expanded' in this future, this must only be done in a manner which "reflect[s] demographic and labour market realities".

Where the Global Compact, with its soft exhortations, is more challenging is in its objectives that all migrants - regardless of their legal status - receive access to basic social welfare services.

That governments should save lives when threatened and establish coordinated international efforts on missing migrants may come as a shock to some countries that believe that mercy is a counter-intuitive policy. Law and order goals to fight human trafficking and smuggling are common sense, but the objective that the detention of migrants should only be used "as a measure of last resort" will be unattractive to some.

So too, the obligation to "co-operate in facilitating safe and dignified return and readmission, as well as sustainable reintegration" of those being exited and citizens who are being returned.

Similarly, objective 17 to some will be troubling. Here, while the objective of calling for the elimination of discrimination against migrants is not objectionable to most, to some the requirement that governments get involved in the "promotion of evidence-based public discourse to shape perceptions of migration" is a step too far, even though the Pact also underlines the commitment to "freedom of expression" and "recognizing that an open and free debate contributes to a comprehensive understanding of all aspects of migration".

The question New Zealand now has to resolve is whether we view the Global Compact as an essential tool that is useful and reflects our laws and values, or whether we view it as an unwelcome prod, no matter how soft, towards views we do not believe in.

Alexander Gillespie is a Professor of Law at the University of Waikato.