UK Prime Minister Theresa May has been unable to convince her own party to pass the Brexit deal she negotiated with the European Union because of its backstop provision. What is it, and why does it m…

Measles cases have spiked as a growing number of anti-vaxxers, opting out of immunizations for their kids, threaten decades of progress toward eliminating the disease.

Jair Bolsonaro has vowed to overhaul Brazil’s economy and align the country more closely with the United States, with uncertain implications for its relations with China.