Many modern historians consider that Trajan's decision to wage war against Parthia might have had economic motives: after Trajan's annexation of Arabia, he built a new road, Via Traiana Nova, that went from Bostra to Aila on the Red Sea.[9] That meant that Charax on the Persian Gulf was the sole remaining western terminus of the Indian trade route outside direct Roman control,[10] and such control was important in order to lower import prices and to limit the supposed drain of precious metals created by the deficit in Roman trade with the Far East.[11]