I think the biggest threat is regulations in agriculture / food production / healthcare. Trying to specify everything in some regulation document always restricts what's possible, and in a bad way, as any document can't describe the whole diversity of system designs permaculturists can come up with. In other words, regulations are almost always dumb.
So permaculturists should push against politicians overspecifying everything.
I think we should treat economics and artificial things that human culture produce in a same way as other parts of ecosystems. In this sense, capitalism is not a threat. Actually they fit well together.
The foundation of capitalism is private property, and that's what needed to implement our ideas on our land: we have to be independent from other people who have different thoughts on what can be done by on same land. Permaculture projects are long lasting and stable property rights are required to make them coming to fruition, to have different stages of succession proceeded as you planned, without some official coming to you in the middle and saying "you are not allowed to do this and that" ruining your work. And with private property, there are multiple independent experiments, so if one person fails his permaculture project, the effect of such failure is limited within his land, but others succeed and find out new interesting patterns others can learn from.
Another clever man:
That's a silly question, loaded as it is. Capitalism is economic freedom, a big economic tent that embraces all sorts of creative endeavor, including small farms and permaculture. If you have studied history, you would know that it was the Russian communists who targeted the kulaks (small, independent farmers) for extermination as enemies of the state system of collective farming. It was also the communists who forcibly shipped the agricultural production of Ukraine to Russia in a deliberate policy to starve out the Ukrainians - the Holodomor (укр. Голодомор).
Here in the US, the Roosevelt administrated prosecuted an Ohio farmer named Roscoe Filburn for disobeying the federal government's control over wheat production. The government claimed he produced more wheat than allowed by the feds, and fined him. Even though he did not sell the wheat in interstate commerce or even anywhere, using it for his own family farm operation, the Supreme Court (which had been packed with FDR supporters by then) ruled against Filburn stating that by withholding his produce from interstate commerce, he was affecting and therefore engaging in interstate commerce.
Bottom line: capitalism (economic freedom) is good for permaculture. Government control is not. It is not in government's interest to have people who are not dependent on it.
And my clarification of Holodomor story:
Holodomor goals were multifold: first, sell the grain internationally to get money for industrialization - they've bought entire plants and factories from capitalists.
Second, ruin the culture of self-sustaining in Ukrainian farmers, and weaken Ukrainian people to decrease the probability of rebellion to fight for independence.