IT’S BEEN TWO months since Osaid Alser has heard from his cousin, Khaled Al Serr, a surgeon at Nasser Hospital in the southern Gaza Strip city of Khan Younis. Before late March, they had been in regular contact — or as regular as the shredded communication infrastructure would allow. Al Serr had created a telemedicine WhatsApp group where he and Osaid, a surgical resident in the U.S., recruited doctors from stateside, the U.K., and Europe to give advice to their overstretched colleagues...