What do Guatemala, Mexico and the U.S. have in common? They are among the very few countries throughout history whose constitutions have guaranteed the right to bear arms.

Our study of constitutions going back to 1789 shows that only a minority has ever included gun rights. What’s more, the number has dwindled, leaving a small and motley set of bedfellows.

For some, this lonely position is enough to suggest that the U.S. should rethink the current interpretation of the Second Amendment. For others, it is a reason to celebrate American exceptionalism.

Either way, the U.S. gun-rights debate raises intriguing questions about how other countries have addressed the issue in their constitutions. When were such rights predominant (if at all), which countries have had them, and how were these rights expressed?

Constitutions have been largely silent about such rights, and increasingly so. Twenty-four constitutions from nine countries have included gun rights in some form since 1789. Most of these constitutions date from the 1800s, and since World War II, no country has written a constitution with such a right without first having done so in the 19th century.

Truly Exceptional

This pattern reinforces the widely held notion that the right to bear arms is a vestige of a distant era. Constitutional customs tend to stick once they are enshrined, even when countries replace or revise their constitutions. While this inertia partly explains the American retention of the right to bear arms, it also shows how truly exceptional gun rights are: Countries that had the right have actively chosen to reject it in subsequent constitutions.

Constitutions with gun rights were reasonably well-represented in the late 1800s: 17 percent had the right in 1875. Since the early 1900s, however, the proportion has been less than 10 percent and falling. As new countries emerged in the interwar and post-World War II eras, their constitutions reflected a modern set of rights.

If arms were mentioned at all, it was to allow the government to regulate their use or to compel military service, not to provide a right to bear them. Today, only three out of nearly 200 constitutions contain a right to bear arms.

We have come to view constitutional rights like a one-way ratchet -- their popularity moves inexorably in only one direction, and that is up. The decline in popularity of the right to bear arms indicates that there is something very different about it, as opposed to other civil, political, social and economic rights. Most probably, the right invokes an anachronism, somewhat like the protection against “quartering soldiers” in the Third Amendment to the U.S. Constitution, or it invokes moral understandings of another era.

Which countries have had such rights historically? In the 19th century, they were mostly in the Americas, and that remains true. Given the strong influence of the U.S. constitutional text in the region, this pattern makes sense. Still, only eight of the 25 or so Latin American countries ever took on the right. The only non-Latin American country to do so was Liberia, a country founded by black Americans who used the U.S. Constitution as a model.

Countries such as Costa Rica briefly experimented with gun rights. Others, such as Colombia, maintained these rights for long spells before dropping them. Most, like Guatemala, have cycled back and forth between omission and inclusion. None has maintained the right continually throughout its constitutional history, which indicates a certain amount of ambivalence.

Right Rationale

For countries that include the right, how do they express it? The U.S., of course, justifies the right in terms of a “well-regulated militia,” but this is unusual. Most constitutions do not provide any sort of rationale, but there are some exceptions.

The Nicaraguan constitution, for example, was introduced in 1987 after left-leaning forces gained control. It provided Nicaraguans “the right to arm themselves in defense of their sovereignty, independence and revolutionary gains. It is the duty of the state to direct, organize and arm the people to guarantee this right.”

The U.S. constitution is alone in omitting any written conditions under which the government can regulate arms and munitions. In other countries, the right is typically limited to self-defense, either of the home or the state itself. Guatemala gives its citizens the right to own weapons for personal use in the home and states that citizens can only be forced to relinquish guns by judicial order. Haiti gives citizens the right to use guns to defend the home but explicitly denies a general right to bear arms.

Of course, U.S. courts have allowed some exceptions to unconditional gun ownership in the form of local, state and federal statutes restricting ownership or possession of firearms. In this way, the courts have served to render constitutional law somewhat less exceptional than the text itself would suggest.

Until 2008, the U.S. Supreme Court had never struck down a law aimed at regulating guns. That year, in the case of District of Columbia v. Heller and, two years later, McDonald v. Chicago, the court held that states could not restrict the ownership of handguns for self-defense. These rulings have made the U.S. even more exceptionally exceptional.

(Zachary Elkins is a professor of government at the University of Texas. Tom Ginsburg is a professor of international law at the University of Chicago Law School. James Melton is a lecturer in comparative politics at University College London. They run the National Science Foundation-funded Comparative Constitutions Project, which analyzes national constitutions since 1789. The opinions expressed are their own.)

To contact the writers of this article: Zachary Elkins at zelkins@austin.utexas.edu Tom Ginsburg at tginsburg@uchicago.edu James Melton at james.douglas.melton@gmail.com

To contact the editor responsible for this article: Paula Dwyer at pdwyer11@bloomberg.net.