John Ternus takes the helm at Apple, stepping into a minefield

During his 15-year tenure as Apple's CEO, Tim Cook has become widely recognized, immensely powerful, and extremely wealthy. Most estimates place his net worth at around $3 billion, wealth he accumulated primarily through performance-based stock awards as Apple's market capitalization increased more than 11 times under his leadership to about $4 trillion.

However, the role also brought significant challenges. Cook had to navigate two Trump administrations and one Biden administration, each with distinct stances on Big Tech, China, and regulation. He also confronted the FBI over encryption, spent years in court defending the App Store against claims that Apple had turned the iPhone into an illegal monopoly, and made compromises to remain in the Chinese market that drew intense scrutiny from human rights groups. Additionally, Cook witnessed the company's most ambitious hardware bet—the Vision Pro headset—flop with consumers. Not to mention AI, where the outcome remains uncertain. Incoming CEO John Ternus inherits all of this.

Below is an overview of some of Cook's most significant battles during his tenure.

The 2016 FBI encryption battle is still fresh in memory. Following a mass shooting at a holiday party in San Bernardino, California, the FBI asked Apple to help unlock the gunman's iPhone. Cook refused, arguing that encryption was the only effective defense against exposing private data and that being compelled to break it would establish a dangerous precedent. The standoff ended when the FBI found an alternative method, but it solidified Apple's reputation as a privacy-focused company and created long-standing tensions with governments worldwide. Ternus will inherit that identity and its accompanying responsibilities.

The App Store antitrust battles have also been challenging for Cook. Epic Games sued Apple in federal court over the requirement that apps use Apple's in-app payment system and its 30% commission. When the judge questioned Cook about why users could not simply pay developers directly at lower prices, his responses did little to ease her skepticism. Apple largely prevailed in 2021, with the court declining to label it a monopoly, but it was ordered to allow developers to link to external payment options. Apple complied in the narrowest manner, charging a 27% commission on those external purchases (some discount indeed), and courts found it in contempt. The Ninth Circuit Court of Appeals upheld that ruling in late 2025, and after a rehearing request was denied last month, Apple is now preparing to petition the Supreme Court, which had already declined to hear its prior appeal. A lower court must still determine what fee Apple can actually charge.

The Epic saga is just one aspect of a broader antitrust war. In March 2024, the U.S. Department of Justice sued Apple, accusing it of unlawfully dominating the smartphone market by restricting third-party app and device developers—such as competing smartwatches, digital wallets, and messaging services—in ways that make it harder for users to switch away from the iPhone. A federal judge denied Apple's motion to dismiss the case, meaning it could drag through the courts for years. Additionally, just this week, Apple revealed that it faces a potential $38 billion fine in India, where regulators found it guilty of abusing its dominant position in the app market and claim Apple has refused to provide required financial data. The case is complicated by the fact that Apple's market share in India is still relatively modest, around 9%, giving it an unusual angle to contest the findings. Ternus inherits this fight mid-stream, with the App Store's revenue model under direct judicial threat.

China has also been a constant and increasingly uneasy balancing act. Cook built Apple's manufacturing operations around Chinese supply chains, making the company deeply reliant on a country whose government became more assertive and less predictable over time. He also made uncomfortable concessions to operate in the Chinese market—most notably removing VPN apps from the Chinese App Store and storing Chinese users' iCloud data on state-controlled servers. Cook proved adept during Trump's first term at shielding Apple from tariffs and trade war risks, partly by cultivating a personal relationship with Trump, who remarked upon news of Cook's retirement that he is "an incredible guy!" Apple has already indicated that Cook will continue to assist Ternus in navigating geopolitical challenges as executive chairman, an acknowledgment that these relationships are delicate and that Cook's institutional knowledge remains highly valuable.

Yet AI is perhaps the most immediate and unresolved challenge that Ternus will face. Apple's AI chief, John Giannandrea, formally leaves the company this month after numerous delays in launching a more capable AI-powered Siri. Instead of relying solely on its own models, Apple has turned to both Google's Gemini and OpenAI's ChatGPT to power some Apple Intelligence features. Longtime market research analyst Bob O'Donnell told Reuters on Monday that Ternus's biggest challenge will likely be "getting a better AI story and offering together that relies more on Apple's own capabilities and less on third parties," although some argue that the company will look smarter in hindsight for waiting out the expensive competition currently playing out among today's biggest AI players.

Last but not least, executive turnover at Apple more broadly is less discussed but significant. Ternus is inheriting a largely rebuilt leadership team following the recent departures of several other Apple executives over the last year or so, including its longtime COO, general counsel, and head of UI design. This is both a challenge and an opportunity that will require him to put his own stamp on things relatively quickly.

The common thread connecting most of these challenges is that Cook's greatest skill was his ability to manage complex relationships with governments and partners while keeping the business running smoothly. Whether Ternus possesses that same skill, or whether Cook's continued presence as executive chairman is intended to compensate for any gaps, may prove to be one of the most interesting questions of the transition.

A more daunting question looming over Ternus's tenure is whether the conditions that made Apple the most valuable company on the planet could actually end. Many industry observers believe that AI agents will become the primary way people interact with services, making the App Store and its 30% commission a distant memory. Combine that with the possibility of compelling new hardware that weakens the iPhone's hold on our lives, such as whatever OpenAI is developing, and Ternus could find himself navigating far more than complex relationships and litigation.