As Phil mentioned, the USFWS' jurisdiction only extends to activities in the U.S. They have no jurisdiction over what occurs in the native range of Asian arowanas. Therein lies the problem.
That's precisely why I believe the ESA should never have been applied to species whose native ranges are entirely outside of the U.S. The Asian arowana was one of the earlier listed species, back in 1976, when USFWS had some pie-in-the-sky notions about the ESA and what it could do.
The Lacey Act and its protections against the importation of wildlife prohibited by international law or laws of other countries should have been enough to ensure that wild Asian arowanas aren't imported into the U.S. Regulation of Asian arowanas under the ESA created a silly situation where captive bred Asian arowanas with CITES documentation are legal under the Lacey Act but illegal under the ESA.
The Lacey Act and its protections against the importation of wildlife prohibited by international law or laws of other countries should have been enough to ensure that wild Asian arowanas aren't imported into the U.S. Regulation of Asian arowanas under the ESA created a silly situation where captive bred Asian arowanas with CITES documentation are legal under the Lacey Act but illegal under the ESA.