In a recent report, Amnesty International claimed that Ireland’s constitutional recognition of the right to life for unborn children is “inconsistent with international human rights law, which does not recognise a foetal right to life and is clear that human rights apply after birth.” The simple fact is that international human rights law grants no right to abortion and is likely silent on the right to life for the unborn.
International law is premised on the doctrine of the sovereign equality of all States. One logical consequence of sovereign equality is that States are free to act in the absence of a direct prohibition. This principle was most famously articulated in the landmark 1927 S.S. Lotus case. In that case, the Permanent Court of International Justice stated:
International law governs relations between independent States. The rules of law binding upon States therefore emanate from their own free will as expressed in conventions or by usages generally accepted as expressing principles of law and established in order to regulate the relations between these co-existing independent communities or with a view to the achievement of common aims. Restrictions upon the independence of States cannot therefore be presumed.
Despite the claim of many international law scholars that this principle no longer represents the status of modern international law, the International Court of Justice indirectly confirmed the Lotus principle in its 2010 Advisory Opinion on the legality of Kosovo’s unilateral declaration of independence. Thus, where international law is silent, States are free to act. International law is wholly silent on a right to abortion. Even the liberal European Court of Human Rights, in A, B, & C v. Ireland, recently recognized that the European Convention on Human Rights grants no right to abortion.
Accordingly, Amnesty International is wrong. There is no right to abortion under international human rights law, and in the absence of this prohibition, Ireland is free to outlaw abortion and grant unborn children the right to life. And from a purely logical standpoint, the absence in international law of an affirmative right to life for unborn children in no way translates into a positive right to abortion. Lack of X does not equal Y; it simply equals not X. This is particularly true under international law, where “restrictions upon the independence of States cannot  be presumed.”
To the natural law school of thought that would disagree with this positivist characterization of the international legal system, natural law only confirms, not undermines, this argument. Modern international law finds its most recent roots in the United Nations Charter, created after World War II. Much of the Charter and its progeny (e.g., the Universal Declaration of Human Rights, the Genocide Convention) were based in natural law and specifically formulated to prevent another Nazi Germany, where the utter lack of respect for human life was at its zenith. Accordingly, much of post-World War II international law embodied the notion that the international community should err on the side of life, even at the expense of State sovereignty. While States were sovereign, natural law mandated that certain things were off limits for all States.
Thus, to the extent that there is any room for debate over whether the unborn are humans, entitled to the same right to life under international law as the born, natural law and the modern roots of international law err on the side of life. Lindsay Jonker, law clerk to the honorable D. Arthur Kelsey, Virginia Supreme Court Justice, explained this best in her article, Learning from the Past: How the Events that Shaped the Constitutions of the United States and Germany Play out in the Abortion Controversy, 23. Regent U. L. Rev. 447 (2011). Jonker compared the U.S. Supreme Court’s abortion jurisprudence to that of the German Supreme Court, specifically examining how the destruction of life under the Nazi regime influenced the German Supreme Court in its abortion jurisprudence to err on the side of the unborn. Jonker stated:
Without our own [U.S.] history to inform us of the consequences of massive violations of human dignity, can the United States not learn from the Germans that, out of respect to life, the fetus must be attributed personhood that merits significant State protection, at any term of a pregnancy?
In other words, history and natural law teach us to err on the side of life where there is any doubt. Germany learned this lesson, and modern international law largely agrees. Accordingly, abortion is not only not a right under positive nor natural law-based international law, but the international community would be well within legal limits, positive and natural, to affirmatively recognize a right to life for the unborn.