The Supreme Court just issued two landmark rulings on rights for same-sex couples in the United States. First, it struck down the 1996 Defense of Marriage Act that denied federal benefits to same-sex couples. And, second, it declined to overrule the California state Supreme Court's earlier decision upholding the state's same-sex civil unions.

Both rulings are a big step forward for American same-sex couples and advocates of greater LGBT rights. But how does the United States compare with the rest of the world on gay rights? The short answer is that same-sex marriage rights are weaker in the United States than they are in much of the Western world. But the longer answer is more complicated and quite revealing.

The map at the top of this page shows where same-sex marriages and civil unions are legal. It also shows countries on the opposite end of the gay rights spectrum: where laws criminalize homosexuality or, in a few extreme cases, allow the state to sentence homosexuals to death.

Where gay marriage is legal: Mostly Europe, some interesting outliers

The list of countries that grant full gay marriage rights is pretty short: 14 countries in all.

Most of those are in Western Europe: France, Spain, Portugal, Sweden, Norway, Iceland, Belgium and the Netherlands. They're joined by two other Western countries: New Zealand and Canada. Also on the list is South Africa, famous for its progressive (but politically controversial) gay rights laws. And in South America, perhaps the most gay-friendly part of the world outside of Europe, both Argentina and Uruguay allow gay marriage. Brazil also looks like it might be on the verge.

Those countries are joined by 12 U.S. states and the District of Columbia. That's actually pretty significant. It means that, even though most of the United States does not allow same-sex marriage, the country as a whole grants those rights to a relatively huge number of people. In all, 56.9 million Americans live in the states with same-sex marriage rights. That's the population of Italy, which does not allow even same-sex unions.

Where civil unions are legal: Europe, South America, the U.S.

This legal middle-ground seems to be most popular in Central Europe and South America, as well as the United States. The rights granted to civil union partnerships vary widely between countries; they tend to be strongest in the United States and weakest in Central Europe.

Same-sex civil unions or some version are legal in 13 European countries, including Germany and the United Kingdom. Some of Europe's civil union rights, such as in Slovenia and Hungary, are quite weak compared to those in other countries. It's also permitted in three Latin countries: Brazil, Colombia and Ecuador. That's it; not a long list.

The eight U.S. states that permit civil unions have a combined population of 78.7 million people. That's about as many people as live in Iran or Turkey.

The U.S. grants a huge number of people same-sex union rights

This is part of what makes today's Supreme Court decisions such a big deal. The court appears to have affirmed the rights of some 135.6 million Americans, who live in states that have passed such measures, to access same-sex marriages or civil unions.

That's a huge number, roughly the same as the populations of Japan or Russia, neither of which permits same-sex unions.

It's a reminder that, even if the United States is in aggregate behind many Western European countries on gay-marriage rights, it still grants those rights to way more people than does any one Western European country.

Homosexuality criminalized in 76 countries

A 2011 United Nations report found that dozens of countries have and enforce laws that criminalize private homosexual acts, a staggering number. That's far, far more countries than allow same-sex unions (although many of those countries are quite small so the number of people effected is not as disproportionate). Most of them are in Africa and the Middle East, although they're joined by some Caribbean and Southeast Asian nations.

Five of those 76 countries include laws permitting the state to hand out the death penalty for homosexuality: Mauritania, Sudan, Saudi Arabia, Yemen and Iran.

I've included this information on the above map to convey that, even as some parts of the world are progressing rapidly on a key area of gay rights, other parts are still so hostile to the issue that simply being a member of this social class is considered a serious crime.

Popular attitudes toward homosexuality tend to be overwhelmingly negative in these regions.