What is a liberal foreign policy? Non-intervention and free trade, including open borders. When it comes to diplomacy, liberal government must be promoted but how it is done must change. You cannot use current Western states as a template. It must be domesticated liberalism, not because it is diminished, but because it is tailored to the people who have to live under that system, which might or might not require a government.
The most important part of liberalism is individual property rights. The principle should be that property can be governed under various systems. The legal system should be based on the current legal system that developed naturally in that place, and it should be the context under which reforms, if any, are made.
Liberalism is about peace, and rational solutions to the causes of violent conflict. The legal system is a key part of that and property rights are the thing that a legal system is meant to defend. We must abandon the idea of revolutionary change. The only revolutionary changes must be the ones meant to restore the people’s law to its rightful place as the supreme law of the land.
All societies have their own laws, and not all of these laws adequately defend natural rights (just like the US Constitution could co-exist with slavery — it is not only the common/customary/people’s law that defends liberty imperfectly), but when we make reforms we must operate under that law, and this is possible once the people who own the law (each and every individual living under the law) have been convinced of the reform.
This would be a policy of persuasion. It doesn’t mean it’s a laissez faire policy. To be persuasive, you have to develop persuasive arguments, and to do that you have to understand the problem as well as it can be understood. That means your foreign intelligence capability must be sophisticated and must be run by people who are experts at data gathering, analysis, and communicating to policy-makers in a way that empowers them to create smart foreign policies. Security considerations should come last.
A foreign policy that offers realistic liberal solutions to our neighbours and other allies, that guarantees neutrality in any conflict that does not threaten our direct interests, would ensure that we do not go around the world creating enemies for no reason, that we make a conscious effort to make everyone a friend and gently persuade them to accept liberal values. We must not use ourselves or our constitution as the template that everyone must follow, that is chauvinistic nonsense and undermines our ability to influence societies outside of South Africa.
Such a foreign policy crucially requires the protection of foreigners’ rights inside our country. A special unit of the police is required in South Africa to deal with xenophobic violence on a full-time basis. We cannot have influence over other states if South Africans treat foreigners in our country badly. A part of this would involve trying to return to the bilateral investment treaties that the government carelessly and unilaterally exited from.
When it comes to defining the core national interests of South Africa, they should be centred on trade and defence of our borders. This practically means that we should not tolerate a more powerful state getting involved militarily in the SADC region, especially in the states that directly border South Africa. It also means that due to our long coastline, we need to have the best air force and navy on the African continent while our army should primarily be a border force. The SANDF should have a small, well-equipped, well-trained expeditionary component for assisting SADC allies.
Military force would only ever be used within SADC. This is for the practical reason that we do not have the resources for more ambitious operations, but even if South Africa gets wealthy enough one day, it should keep the same policy of military intervention only within SADC and only by invitation unless the government of that country is the aggressor against South Africa. A non-interventionist foreign policy would make us wealthier and safer; it would also make us peacemakers all over the world.
This is not new in South Africa. It is similar in many respects to the foreign policy developed by President Thabo Mbeki and which is still followed by the South African government to some extent: Negotiate peace between warring parties, stay neutral and do not favour one side or the other, persuade the leaders of other countries to implement reforms, and trade with all. This is a liberal and rational foreign policy. It is about making peace instead of imposing our vision on other peoples and triggering unintended, horrifying, and permanent consequences, because societies are complex.
 Security being distinct from national defence, a foreign policy based on promoting peace is also a good long-term national defence strategy.
 It depends on requirements, but due to our limited resources, a ~5,000 man joint service expeditionary force configured to deal with the most common threats in SADC and the states bordering SADC. It should also conduct regular exercises with our neighbours’ militaries to develop effectiveness for joint operations.