Sri Lanka suffered almost 33 years of LTTE menace because of not paying proper attention to its defense capability. India manipulated Sri Lanka's LTTE situation by using muscle power. During the conflict with LTTE, Sri Lanka was begging for help from Pakistan and India, and sending their military personnel to those two counties plus Bangladesh for training. Pakistan sent its officers and soldiers to design military strategies and even to fire Pakistan-supplied howitzers or MLRSs. However, when Sri Lanka finally defeated LTTE in 2009, they subsequently canceled all the defense procurement contracts with Pakistan.
In my opinion, even in peacetime, a powerful military helps a country to pursue a semi-independent foreign policy. Sri Lanka doesn't pursue a semi-independent foreign policy.
- Nowadays, Sri Lanka is wedged between India and China's tug of war. One day Sri Lanka gives away concessions to China, on the next day it balances that by giving another concession to India.
- In 2016, Sri Lanka backed off from the purchase of JF-17 fighter jets from Pakistan under Indian pressure.
- In 2021, to avoid a clash with India, Sri Lanka cancels Pakistan's PM's speech in their Parliament.
Why does Sri Lanka have so small a military? Why don't they try to develop their military?
For example, almost all the neighboring counties of China have strong militaries. See Taiwan and Vietnam.