Refugee advocates can never summon the courage to answer the question of how many is too many. Instead, they hide behind the particular instance, always ignoring the big picture. Governments, on behalf of all Australians, cannot ignore the big picture. The morality of the few is not the same as the morality of the many.

An overly legalistic and generous refugee regime, detached from its consequences, makes Australia vulnerable to large numbers of refugees. The effect, if indeed not the object of refugee advocacy, is to disarm Australia. The law for one creates the problem for many. This is the nub of the issue, and politicians, not lawyers, have a responsibility to solve it.

It was, therefore, with some amusement that I listened last week to David Marr’s ABC FM Radio Classical interview with Renata Kaldor. Renata, along with her husband Andrew Kaldor, established last October the Centre for International Refugee Law at the University of New South Wales.

The centre’s founding director, professor Jane McAdam, is, we are informed, “one of the world’s leading international refugee law scholars”. She has said the centre aims to bring “a principled, human rights-based approach to the issue of refugee law and policy in Australia by feeding high-quality research into public policy debates and legislative reform”.

What principles, and more especially, what policies are these?

McAdam writes, “Relative to the rest of the world, Australia receives an extremely small proportion of asylum-seekers: only 2 per cent of the industrialised world.” So, it is a numbers game. What is better, 3 per cent, or 4 per cent? The law cannot determine that number. Human rights provide no guide: except apparently the more the merrier.

Refugees flee poor countries because they are at risk of death or serious harm. The reasons for their plight are many, but essentially, the people in these nations have not, and may never, arrive at the formula for governance that liberal democracies discovered in generations of painful struggle, starting with the English revolution of 1640 to 1660. Australia has, and more importantly Australians have, developed the habits of liberal democracy.

Australians do not tear themselves limb from limb, but graciously accede to an election loss and know that, in losing, rights to treatment under the law will be preserved. The same is not true in those nations, or bits of them, from which refugees flee.

Paul Collier’s fine study, Exodus: Immigration and Multiculturalism in the 21st Century, proves that the immigration from poor countries to rich is on the rise. The numbers of those who want to take the protections of the liberal nation state, but potentially forsake its disciplines, are also on the rise.

Collier’s thesis is that, left ungoverned, as has occurred in Europe, migration will accelerate and become excessive. This is why migration controls, far from being an “embarrassing vestige of nationalism and racism”, are important tools of social policy.

He asks “suppose that international migration would become sufficiently common as to dissolve the meaning of national identity”.

He makes plain what is obvious to almost all Australians, that a national identity and a clear set of rules that all citizens obey are the price of liberty. More powerfully, he argues, “nations are important and legitimate moral units”.

Immigration policy that is “less than an open door” is not mean spirited, and in a powerful rebuttal of our internationalist heroes, “nations are not selfish impediments to global citizenship”, they are the only way to provide public goods such as pensions and security. He comments on our boatpeople situation and makes the point that Australians have the right to restrict entry.

Diversity is beneficial, up to a point, and while globalisation should eventually lead to convergence in incomes between rich and poor nations, until that time the vulnerability to over-large migration flows is serious, for host nations and sending nations.

Permanently rising cultural diversity runs the risk of undermining mutual regard. Migrants hanging on to unacceptable practices that prevailed in their countries of origin at the time of migration may cause harm in the host nation.

Neither judges nor academic lawyers can determine how many immigrants-refugees are enough. Only the citizens, who have attained the habits of the liberal democracy, and who must live with the newcomers and indeed help their integration, can determine how many is enough.