The U.S. Navy’s dominance of the world’s oceans has made it an indispensable foreign policy tool and a guarantor of global trade, but a mix of challenges is raising difficult questions about its futu…

The U.S. government responds to scores of disasters each year in coordination with foreign, state, and local partners, but more frequent and severe storms, fires, and floods are straining resources.

Modern vice presidents can trace much of their political influence to the broad reforms that Jimmy Carter and Walter Mondale made to the second-highest elected office in the late 1970s.

Brazil has long sought a greater role on the world stage, but political upheaval and other enduring challenges have complicated its efforts.