Why did Portuguese spend 40% of their national budget in the wars to keep their African colonies?

My African cliche of the day is a burden. The economic burden suffered by the African continent, because of all the struggles for independence. Historians often focus on the burden and impact that slavery imposed on Africa. What if we were to calculate the economic damage of all the independence fights and war ? what do you think should be taken into account ? What is the price of an African independence? It’s up to you to think about it, to think about your own willingness to pay for freedom.