As for the "geographical position" argument, there are many routes--by sea or air--direct from Southeast Asia to North America. Also, the free ports of Hong Kong and Singapore lie directly along those routes, and there is no essential reason for drug traffickers to go out of their way to take drugs into Taiwan only to re-export them later.
就地理位置來說，東南亞金三角到美國的航線密集，中間還有香港和新加坡兩個自由港，沒有繞道台灣的絕對必要。