Anarchists can organize and fight militarily quite effectively while still maintaining a bottom-up system, as demonstrated by the Anarchist militias of Makhno and Catalonia (and though not Anarchist, Rojava is an example of a decentralized army). The issue all Anarchist attempts have faced militarily is a lack of any allies on the world stage, allowing the authoritarian nations around them to crush them due to lack of supplies (or sudden betrayal of ML ‘allies’).
Anarchists can organize and fight militarily quite effectively while still maintaining a bottom-up system, as demonstrated by the Anarchist militias of Makhno and Catalonia (and though not Anarchist, Rojava is an example of a decentralized army). The issue all Anarchist attempts have faced militarily is a lack of any allies on the world stage, allowing the authoritarian nations around them to crush them due to lack of supplies (or sudden betrayal of ML ‘allies’).