SoftBank and Naver helped bridge geopolitical relations with a joint venture to own the operator of the messaging app Line, but now the partnership is fraying.

SoftBank and Naver helped bridge geopolitical relations with a joint venture to own the operator of the messaging app Line, but now the partnership is fraying.
Mr. Musk, the owner of Twitter, is the latest Silicon Valley mogul to pursue an all-in-one app, the kind that has thrived in Asia but not elsewhere.