What did truman mean when he claimed," should we fail to aid greece and turkey in this fateful hour, the effect will be far reaching to the west as to the east"?

a politically correct answer.

northernmost part (disputed, administered) - near indira col, siachen glacier - 35.674520°n 76.845245°e

northernmost part (disputed, claimed) - dafdar near beyik pass - 37°24′00″n 75°24′00″e

northernmost part (undisputed) - near dharwas, chambal district - 33.24902°n 76.82704°e

southernmost part (mainland) - cape comorin - 8.06890°n 77.55230°e

southernmost part - indira point in the nicobar islands - 6.74678°n 93.84260°e

distance between:  

1 & 4 - 3070 km

1 & 5 - 3654 km

2 & 4 - 3269 km

2 & 5 - 3885 km

3 & 4 - 2801 km

3 & 5 - 3430 km

explanation:

b. ensure mutual protection from communism.

.