One is definitely tourism.
Explanation:
The factor that jeopardizes the ecosystem in Eastern Europe is the tourism industry. Individuals simply travel there and have a fabulous time yet they don't pay attention and leave beaches dirty. They are not dealing with nature and the administrations can't do much since sightseers leave a lot of money for the nations.
Pan Arabism is a political movement promoting the idea in which Arabs should unite in forming one country or a state. The idea was first done during 1800s in the later part and 1900s.If this stayed it would have led to greater unity for Arab and countries like Egypt and Syria could have stayed united which is the answer.
Less dense then water its self
By ocean currents is the answer to your question