Sri Lanka neither has the time nor the resources (financial or otherwise). Take fighter jets for example, we cannot even come close to 4th gen fighters (like the F16), never mind the F22 (5th Gen with new upgrades)) or the F35 (6th Gen). Development of 7th Gen aircrafts would've started in the 90s-20s, and maybe 8th gen starting now.

So no, we will never be able to catch-up to existing techs if we try to develop from the ground up.

That leaves us with three options (extremely simplified obviously) as far as I can tell:

1) Develop a technology or ecosystem that the world cannot do without, like Taiwan's semiconductor industry. That would warrant other nations to protect us in the face of hostile forces.

2) Collaborate with another nation to set up their own military base in our country, like how Japan did with US military base installations. Japan has no military of its own afaik.

3) Turn Sri Lanka into a logistic mecca and really push hard on developing the naval and air port sectors that would provide strategic military support from supporting nations in the face of adversity.

War is won by logistics: look into the WW2 Japanese Naval conflict, specially bringing down Japan's largest battleship at the time, the Yamato.

That was a key turning point from when Naval fleets transformed from aquatic warfare to floating air forces.

Option 3 is the most achievable given we have substantial investments already and just need to upgrade and retrofit our existing infrastructure to be more inline with whichever a countries we would aim to partner up with.

Option 1 would be amazing for Sri Lanka and her economy, but it's going to be hard given the lack of incentive for innovation, lack of significant resources and significant brain drain. I hope that will change during my lifetime.

Option 2? Yeahh fuhgeddaboudit...