Remarkable.

An Arab nation has policed another Arab nation.

The kingdom of Saudi Arabia dispatched troops on Monday to the kingdom of Bahrain, an island in the Persian Gulf, to quell a monthlong uprising that had called for democratic reforms, much like many of uprisings in the Islamic world this year.

That is how it should be.

The United States introduced the Monroe Doctrine in 1823, asserting its influence over North and South America. When there is trouble in the Americas, the United States has the responsibility to step in and police its corner of the world.

In turn, the United States should not be in the business of policing the entire world.

When nationalism among ethnicities in the former Yugoslavia led to war in the 1990s, European nations failed to lead the effort to bring peace. It took the United States to lead the international community, when it frankly should have been the European nations. After all, that war was in their own backyard. Europeans should have brokered peace in Europe, not the United States.

While calls for democracy in the Middle East are good for the spread of power for the people in those places, the United States should not be in the business of nation building on the opposite side of the planet. There are countries with great powers on that side of the planet to handle the work.

The nation building the United States needs to focus on is that of building the United States, which is recovering from an economic slump. We already — hopefully — have learned much about how war can lead to massive federal debt, damage the economy and end of the lives of sons and daughters, all for questionable reasons. What could start off seeming like a quick attack might end up a spending quagmire.

Should there be a no-fly zone in Libya? It’s not a choice the United States needs to make.