(Seoul) The last four members of the legendary K-pop group BTS who have not yet completed their military service have begun the process of joining the South Korean army, their label announced on Wednesday.

The septet has become a global cultural phenomenon in ten years, brought in colossal sums of money to the South Korean economy, and is followed by an international “legion” of fans known as ARMY.

But all able-bodied South Korean men must complete at least 18 months of military service. After a years-long debate over whether BTS deserved an exemption, Jin, the group’s eldest, began his service in December, his bandmate J-Hope in April, and a third member, SUGA, in September.

The group’s four remaining members – RM, Jimin, V and Jung Kook – are expected to start their own soon, their label, BIGHIT MUSIC, said in a statement.

“We would like to inform our fans that RM, Jimin, V and Jung Kook have started the process of enlisting in the military,” the label announced.

“We ask that you continue to love and support RM, Jimin, V, and Jung Kook until they complete their military service,” the statement added.

Analysts wonder about the future of the group once the seven members are released from their military obligations.

Some male K-pop stars have struggled to resume their careers after serving in the army, in an industry where artists are easily replaceable.

Last year, BTS announced they were taking a “break,” citing exhaustion and their members’ desire to focus on their solo careers. Some saw this as a consequence of the specter of conscription.

However, the HYBE agency announced in September that the seven members of the group had all renewed their contracts with it, which suggests that they intend to resume their careers once they return to civilian life.