Russia possesses the world's most Arctic shoreline, water, and operating resources. But the United States is also an Arctic nation, even if much of the American public tends to under-appreciate this special status.
Off the western coast of Africa, just north of the equator, the Gulf of Guinea has endured piracy for decades. But recent spikes in new, more dangerous forms of piracy imply a troubling sense of invincibility in the minds of the perpetrators.
Preventing Iran from becoming a nuclear weapons state would contribute to global security, and especially to the security and stability of the Middle East, but these are not the only considerations at hand.
As much as China may wish to lean on Russia should Beijing find itself at odds with the United States, Xi seeks a new type of great power relationship with the United States that calls for mutual respect, no confrontation, and cooperation.
Russia's annexation of Crimea is proving costly. If Putin thought seizing Crimea would make the rest of Eastern Europe deferential to Moscow, the opposite is occurring, as anti-Russian/pro-NATO sentiment surges throughout the region.
Despite the smaller number of U.S. troops in Europe, the military balance there is far more favorable to NATO today than it was when nearly 10 times as many American soldiers, sailors and airmen were stationed on the continent.
There needs to be more frank and precise thinking about the kind of support allies are able and willing to provide. Counting on Europeans even just to pull as much weight as they have in the past is an increasingly doubtful proposition.