Which of these is the main unifying factor for most people who live in southwest asia?

The main unifying factor for most people who live in Southwest Asia is religion.

A region is the places in the world that share something in common. Southwest Asia is a good example of region as it shares many things in common, especially religion. Many people follow Islam here. A large number are also from same ethnicity, Arab, although there are many other ethnic groups in the area.

first, the romans stayed isolated because they had to defend their own territories from neighboring cities that were harassing them, like the etruscans. second, once the romans managed to defeat their neighbors, and started to expand their territory, they started to build roads and bridges. finally, now that the romans have covered their territory with roads functioning as highways, they could mobilize their legions faster to assemble larger military units in a specific place.