Arrange the following criticisms of the Heartland Theory in chronological order of their prominence:
- Rise of air power reducing geographic isolation.
- The Soviet Union’s collapse in the late 20th century.
- The Cold War’s impact on strategic focus.
- Advancements in global trade networks reducing regional isolation.
1
3-1-2-4
2
4-1-3-2
3
1-4-3-2
4
1-3-2-4