Not 100% what region your talking about but the colonists pushed into native American lands stealing them and killing them when they refused to move.
Colonist also brought diseases from Europe that killed a large number of the native population and creating fights with them. Native Americans would raid colonies and vice versa.
Answer:
it's the Euphrates River
Explanation:
The river rises in Turkey and flows southeast across Syria and through Iraq.
It would be under the policy of Containment otherwise know as the Eisenhower Doctrine.