What allowed countries to call up troops and move them quickly?

How were castas paintings used to stabilize a society?

Since the 700 what was the relationship between muslims and christians on the iberian peninsula? how does this relationship impact the desire of christiannations in the iberian peninsula to spread christanity?

Two gymnastics teams are intense rivals. the first team has started recruiting new gymnasts from different cities and even foreign countries in an effort to build a stronger team. after learning this, the second team begins its own recruitment campaign to find even better gymnasts. over a period of months, each team recruits dozens of players, each time trying to find a better recruit than its rival's most recent addition. which idea from the cold war is most similar to this scenario?