The Ultimate Guide to Travel Insurance for Unpredictable Times

John Popovics thought he’d done everything right.

Earlier this year the University of Illinois at Urbana-Champaign civil engineering professor was planning a trip to Riyadh, Saudi Arabia, to take part in a National Science Foundation workshop. Because the costs were adding up quickly, he chose cheaper, nonrefundable options for his flights and hotels — as well as the Travel Guard insurance that United Airlines Inc. offered.

“I walked in thinking, ‘Travel insurance is good, and it will protect me,’” he says. Popovics scanned his policy, noting the many scenarios it covered, from lost luggage to a terrorist attack.

Then the US attacked Iran in ...