The Arakan Army started as a small group of 29 cadres in 2009 under the guidance of the KIA in Kachin State.
It has come a long way since then, according to recent independent estimates such as from the Jamestown Institute, the Arakan army now includes at least 40,000 regular soldiers, with some estimates placing it higher at around 50,000.
This makes it the largest unified non-state actor in all of South and Southeast Asia.
In addition, they are one of the rare groups that manage to effectively utilize the captured junta's heavy equipment including armored vehicles and heavy artillery.
They are by far the most professional fighting force in the country with heavily enforced OPSEC rules, strict discipline and high level leadership.