Relations between the two countries, long bound by common interests in oil and security, have strained over what some analysts see as a more assertive Saudi foreign policy.

One of the world’s most-watched news networks is at the center of a geopolitical rift between a Saudi-led bloc and the broadcaster’s funder, Qatar.

Military power has reemerged as an important component of Russian foreign policy, which some believe aims to reestablish Russian hegemony in the region.

The U.S. transport system is badly in need of infrastructure investment, and the country could suffer competitively if the status quo persists.

The Muslim separatist group, based in the Xinjiang province in northwest China, presents a heightening security challenge for Beijing.