It is good that you weren’t around in 1775 in America or in 1979 in Afghanistan. You’d probably be telling everyone to give up because they didn’t have foreign sugar daddies to help them.
No insurgency has won without the support of an outside major power. The US would not have gained independence without France. Russia would still be running Afghanistan without the US, Pakistan, and the Saudis.
Without these outside ‘sugar daddies’ neither America or Afghanistan would have seen victory.