Maybe it is not obvious, but many military interventions in history were lead by private capitalist companies pr rich men armiea. From civil wars in the Roman empire to colonisation of Central America, India, etc. and more recently western interventions on Africa serving private interest (intricated with geopolitical ones).
Depending on the donations of the super rich is like depending on the will of kings... You do not agree? You loose it. This has also always happened in non capitalist contexts, but they are/were not anarchist.