Romans 10:21

Israel : a citizen of Israel.,a member of the nation of Israel

Romans 15:31

Jerusalem : the capital city of Israel,a town; the capital of Israel near the southern border of Benjamin
(31° 46´, 35° 14´); (31° 46´, 35° 14´); (31° 46´, 35° 14´); (31° 46´, 35° 14´); (31° 46´, 35° 14´); (31° 46´, 35° 14´)

Judea : a region that roughly corresponded to the earlier kingdom of Judah
(31° 46´, 35° 14´); (31° 46´, 35° 14´)