According to Engadget, US Army spokesman Lieutenant Colonel Robin Ochoa told Military.com that TikTok was considered an online threat. The commanders began alerting soldiers in mid-December, almost at the same time that the Ministry of Defense asked the staff to remove TikTok to avoid any incidents of revealing personal information.
The U.S. Army is concerned that the Chinese company owns TikTok – ByteDance, which could cause security problems. Although there is no evidence of suspicious activity taking place, ByteDance may be forced to transfer sensitive information of US soldiers to the Chinese government or recruit soldiers to spy. The company has objected to such claims, to the point where it can sell control of TikTok to reassure US officials.
It is unclear whether the Air Force or Marines will implement similar policies, but this is entirely possible.