The drive for autarchy (full self-sufficiency) is an idiot's quest. It bespeaks of either failure of foreign policy, or failure of understanding of economics, most likely both. One of the most basic principle of economics is expressed by Richardo's law of comparative advantage. It in effect says social wealth is maximized only if each party restrict itself to producing only that in which it enjoys the greatest comparative advantage in efficiency, and trade for everything else it needs.
This is why successful countries don't put itself in the situation that requires it to produce everything it needs for defence itself. Countries which strive for total self sufficiency in defence during peacetime, like the USSR and Nazi germany, or North Korea, tend to be diplomatic or economic failures.
Wrong.
All depends on the parts are critical or not. If parts non ciritcal and it can easily do themselves then outsourceing is OK.