It's about sovereign interest, and if you rely on foreign assistance to run state, you are a vassal at best. Last time I checked, Russia is still holding onto annexed land in Ukraine, and there is a proxy war in Yemen, the Korean peninsula is prepared for a full blown conflict at any moment, hostilities between India and Pakistan, and on, and on, and on, and on. There are absolutely ambitious geopolitical interests at play willing to use brutal force as a means to obtain their goals at costs most people cannot comprehend. It's probably advantageous to have your own tech and verticals for building it domestically. I mean it's not like securing uranium deposits.
