How is libertarianism affected by national borders?

To what extent should Australian libertarians seek to oppose coercion in other countries?

Libertarianism is all about the freedom of individuals from coercion. Libertarians believe the proper role of government is defined by JS Mill's harm principle: 'The only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others.'

Within a country this is relatively straightforward – reductions in tax and increases in liberty are supported, increases in tax and reductions in liberty are opposed.

But things can get complicated when it involves matters outside the country. How is libertarianism affected by national borders? Can it apply to relationships between sovereign states? To what extent should Australian libertarians seek to oppose coercion in other countries?

In his 1801 inaugural address, US President Thomas Jefferson declared that the US should consider its external military alliances to be temporary arrangements of convenience to be abandoned or reversed according to the national interest. Citing the Farewell Address of George Washington as his inspiration, Jefferson described the doctrine as "peace, commerce, and honest friendship with all nations-entangling alliances with none."

Known as the Washington Doctrine of Unstable Alliances, this thinking dominated US foreign policy right up to the Second World War. And although America now has longstanding alliances with many countries, including Australia, the doctrine remains influential in some political circles.

In particular, many libertarians support it. In their view, a country should not invest blood and treasure in squabbles beyond the country's borders unless there is a clear threat to the country and its ability to engage in trade and commerce. It should certainly not maintain military capabilities in excess of what is needed to defend the country.

This is rationalised in terms of libertarian values. History has repeatedly shown that a standing army is a threat to liberty. Moreover, maintaining a military force capable of more than simply defending the country is expensive, necessitating higher taxes than if the Washington Doctrine applied.

They point to wars such as Vietnam, Iraq and Afghanistan, where it is difficult to show any enduring benefits from military involvement by America or Australia. They also criticise current support for Ukraine's fight against Russia's invasion.

There is a problem with this thinking though: nationalism and national sovereignty are collectivist concepts. They are not libertarian and, Jefferson's other qualities notwithstanding, neither is the Washington doctrine.

What that means is, there is no libertarian justification for doing nothing about coercion merely because it is occurring in another country. Coercion should always be our concern, wherever it occurs.

That does not necessarily mean rushing military aid to those subject to coercion in other countries. There are many reasons why that might not be possible, practical, or advisable. Sometimes it might make sense; sometimes not.