Most dictatorships are paper thin. A few people with guns, tanks, and fighter jets can hold down millions of others without those. Those few people are easily defeated when facing a superior external force though, even if they have millions of supposed troops (these are willing to surrender immediately). Examples include Iraq, Afghanistan, etc in frontal battle with foreign troops.

Even if the fight IS hard and kills many people, it is worth it right? Or do you want your wife to disappear for four years and be kept in a black prison? Or do you want to watch millions of ethnic minorities being murdered in concentration camps?

It's better to fight, risk death, and be free than to cower in fear while your loved ones are tortured and murdered.