How Europe’s regulatory battle with Apple could signal what’s to come for American consumers

It’ll likely take years before the U.S. government’s massive antitrust lawsuit against Apple is resolved — but the iPhone maker’s troubles with European regulators offer a glimpse of what changes American customers may see down the line.

The U.S. lawsuit seeks to stop Apple from undermining technologies that compete with its own apps in areas such as streaming, messaging and digital payments. The Department of Justice also wants to prevent the tech giant from building language into its contracts with developers, accessory makers and consumers that lets obtain or keep...