Muslim/Christian Trade

This weeks readings of the book, Before European Hegemony talked about trade through the middle route. The violence of the crusades or the Papal injunction did not stop the trade from prospering between the two. The Musilm merchants and the christian merchants had actually developed a relationship over the years. The trade between the middle rout was a major contributor to the prosperity of the chief port for the crusader colonies, Acre. Acre was controlled by the venetian colony. The Venetians seemed blind to the fact that their priveleges were about to come to an end. Mamluk sultan had reign over the remained peaceful in the latin states of Syia. However, needing replacements for his troops, another treaty with the Genoese was carried out. It guaranteed safety of each countries merchants, but by that time the trade across the inland route had declined immensely. The truce ended in 1921 when Qalawun's son, the successor, drove the crusaders from their last port in Acre. The Venetians and Genoese had to find ways to gain access to the silks and spices of the far east. One alternative was to use the northern overland route and another was to work through the II-Khans of Persia who allowed European merchants to pass through their territory. The most daring alternative was to circumnavigate Africa by means of the Atlantic and gain sea access to the Indian ocean. Two brothers, Ugolino and Vadino tried this third alternative but they were never heard from again. THe trade continued through the second alternative. Europeans had to deal with muslims inhabiting their territory. The only "free" passage was through II-Khan territories to Hormuz on the Persian Gulf. Then they could set sail to India. I thought it was interesting that neither the crusades nor the Papal injunctions diminished trade between the inner route to some degree. It seemed as though people viewed the Papal injunctions as something informal. Although it prohibited Europeans to trade with muslims as well as one being in place between the European traders with the "infidels", it didnt seem to stop people from breaking it.
I was wondering if there were any other alternatives that the Genoese and Venetians did not think of that they could of utilized at the time?