They're listed under CITES appendix 1, which means they're critically endangered in the wild. With the US being signatories to the the CITES treaty, all endangered animals under appendix 1 are illegal to possess in the US without a permit under the Lacey Act. FWS has the power and authority to issue permits, they just won't under any circumstances. Getting a permit for an Asian aro is about like getting a permit for a eagle, cheetah or a rhino: it's theoretically possible, but it won't happen.