here i ask one question, how do think of a countries weapon manufacture ability? is it important. and take example, if country A can purchase the most advance weapon,(maybe from US, russia) but it cannot assembly its own advanced tech, but for nation B, it can make its own weapon while is some one generation lags behind the country A weapon.

now assume we can only choose only one type, which type will you prefer?
A: can buy but cannot make
B: can make but cannot buy, also, it is one generation outdated.

for me, i will choose type B

Either way, you're buying/building a generation away from state-of-the-art weapons. I think doing research and building yourself will help the learning process leading to more advanced generations. Take B.

With the speed of modern warfare I'l go with option A. The days of assembly lines pumping out war equipment in mass are over.

All the work goes into getting the weapon fully operational from the design board and getting all the bugs out of it so that it does what it is designed to do.

I would say A.
No-one can compete with the U.S./Western Europe for technological superiority of weapons.
If a country's in a situation where the U.S. wont sell them weapons chances are they're the enemy.(or allies to your enemy) and you're F***ed anyway.

Is there an underlining message to this thread? Would country B happen to be China? In any case, I would have to go with option A. Why? Because you can buy the most advanced weaponry and then reverse engineer it to how it works and then make your own version or a better version. In today's world, money talks. If you have a lot of it, why waste your resources researching weapons when you can buy the best ones out there. Use your resources to further expand your economy or improve living conditions in your country.

If you can manufacture but don't have the means to buy it tells me the country is low on capital and if they are low on capital it would follow that the weapons they do produce will not just lag behind in technology but also in quality see the former Soviet Union for example.