What is China’s aircraft carrier Liaoning testing – and why does it matter?

China’s first aircraft carrier tried new tactics in its latest drill – including working with land-based tanker aircraft and coordinating with an amphibious assault ship – amid a push to strengthen military combat capability.

The Liaoning aircraft carrier strike group returned to its home port in Qingdao on Monday after completing more than 40 days of far-sea combat training, according to state broadcaster CCTV.

During the extended deployment, the Liaoning conducted combat exercises at multiple...