Palestine became a contested territory during the 20th century in part because:
B. Both Arabs and Jews in the region were becoming more nationalistic.
In the end of the 19th century and begining of the 20th, a movement called Zionism became to grow. The zeal to return to Zion, the land of their forefathers, became a secular and political movement.
At the same time, several arabic newspapers appeared in the begining of the 20th century showing the strengthen Arab nationalism and oposition to Zionism. They pretended to put an end to Jewish inmigration and purchase their land.
Conflicts aroused between Arabs and Zionists leading to violent encounters and, in some ocations, open warfare.