Musk Effort to Kill Deal Leaves Twitter With Only Bad Options

Elon Musk’s effort to dump his agreement to buy Twitter Inc. leaves the social media service worse off, no matter the outcome.

If the Tesla Inc. chief executive officer succeeds in ending the deal, Twitter stock will likely free-fall, and a staff already dejected by Musk’s months-long public criticism of the site will suffer another emotional blow. If Twitter prevails in court, the company will be run by an unpredictable and reluctant owner, while still struggling to meet ambitious growth targets.

Musk’s regulatory filing Friday announcing plans to walk away from his $44 billion purchase touched off a nightmare ...