China and Russia have expanded trade and defense ties over the past decade, but they’re not formal allies. Experts say Russia’s war in Ukraine could be a turning point in the relationship.

The alliance with Japan has been the cornerstone of U.S. security policy in East Asia for decades. Now, Japan’s role in global security is growing as challenges from China and North Korea mount.  …

A long-lasting security alliance with the Philippines remains at the heart of U.S. strategy in the Asia-Pacific, a region that includes the disputed South China Sea.

The sprawling U.S. water system is central to the nation’s economy, but chronic underinvestment, increasing demand, and the consequences of climate change have revealed the system’s weaknesses.  

U.S. missile defense in the twenty-first century is focused on emerging threats from North Korea and Iran, but critics say these systems are too costly and largely unproven.