The correct answer is Israel.
The creation of Israel is a major cause of the hostility toward the United States by terrorist in the Middle East.
On May 18, 1948, The Jewish Agency through its leader, David Ben-Gurion, officially proclaimed the establishment of what is known as the state of Israel in former territories of Palestina in the Middle East. This declaration was supported by the United States President Harry S. Truman, and since that same day, the decision has caused many conflicts in the region, included violent ones and terrorist attacks. So it is true that the creation of Israel is a major cause of the hostility toward the United States by terrorist in the Middle East.