Last month, King Hamad bin Isa Al Khalifa of Bahrain and Qatar’s Emir Sheikh Tamim bin Hamad Al Thani met on the sidelines of the Jeddah Summit for Security and Development. On the same day, the Bahraini Ministry of Foreign Affairs lifted Qatar from its travel ban list and abolished visa requirements for Qataris to enter the archipelago kingdom. Both events signify important developments in the thawing Bahraini-Qatari relationship after years of tensions.

Ties between Manama and Doha were particularly tense following the eruption of the Gulf rift in June 2017. Bahrain joined Egypt, Saudi Arabia and the United Arab Emirates (UAE)—jointly constituting the Arab Quartet—in cutting ties with Qatar and imposing a blockade on Doha over what they claimed was support for terrorism and regional destabilizing role. The severing of relations entailed the closure of embassies in Doha and expulsion of all Qatari diplomats...