I find it hard to believe that the US government is going to do much helpful in terms of preparation. If they actually do, it would seem to go together with the kinds of things I am talking about.

I expect the government will try to let higher prices sort things out, and this really won't work (or perhaps put in price controls). We will end up with shortages and perhaps riots.

In the 1930's for example there was no way for concerned individuals to prepare rationally for the threat of Hitler without knowing in advance the actions of their own national governments.

The rise of Hitler was a corporate one, government went along for the ride. Individuals that collaborate with corporations instead of acting for their own interest (buying prepared/processed food instead of growing it, for example) don't give up their freedoms to government, but to corporations. The government has constitutional limits to its atrocities (well, the ones they don't ignore at the behest of corporations, anyway).

Cuba's example is one where people were already poor, so it doesn't necessarily fit how we get started on a Descent plan, but their cooperation and fortitude to endure until their localized markets and gardens could compensate for the loss of centralized supplies is commendable.

The critical fulcrum is how much Systematized support we are going to force the government into. A country of independent farmers and small businesses would force the government toward Rooseveltian socialism and distributed logistics. A country of systems-dependent urbanite technocrats would force the government toward centrally planned corporatocracy and control-point logistics (look for the stories about detention camps, consolidated meat processors, factory farms, ID chips in babies and animals, Prozac in the water supplies, etc). The latter would eventually fail anyway, due to its dependence on inputs of energy, chemicals, drugs, and suppression, but it would be a sadder road to follow than one of cooperation and compassion.
The Corporacrats will claim that "We don't have a cow and garden in every yard anymore, so we have to provide food to people through our infrastructure."
Better to PUT a garden in every yard NOW, then, dontchathink...maybe a goat to mow the lawn instead of gasoline?

Our government, at the federal level, is worse than useless. Policy is bought and sold by corporate interests. Some profit from violence, many profit from chaos(think hedge funds), and most cease to exist with the removal of essentially free global transport. The projection of military force requires vast amounts of fuel. All of these things going away look like "the end" for a corporate interest and they'll be as suicidal as an individual can get. We, The People are going to end up in polarized opposition to the state before this is all done.

"I'm always concerned that any individual or community preparations, however intelligent or prescient, will be swamped and rendered useless or worse by unpredictable - but then overwhelming - national government actions, once governments actually are moved to act."

I tend to agree that preparation at the level of an individual family has a high probability of being overwhelmed by shocks to the larger economic system. Community level (neighborhood, town, county, bio-region etc) changes have a somewhat better chance of providing some degree of economic protection. However, it is unlikely that any of these levels of community organization will become completely independent from the national and global economies in the near future, so that shocks from these larger systems will be felt everywhere.

Unfortunately I also agree with Gail that the chance of national governments providing any real leadership in this crisis is near zero. National governments remain utterly committed to short term corporate profits and to allowing financial speculators a free hand. Every other consideration is secondary to these primary commitments.

I believe that a sustainable economic future requires the development of a system of democratic social investment whose object is to produce long term sustainable wealth for the community and not to increase the purchasing power of individual investors. We need to be able allocate production resources to enterprises which we perceive to be valuable for the community without paying private financiers for the privilege of doing so. We need to create a wealth maintaining economy rather than an economy that is committed to constantly increasing levels of wealth. A social and political revolution is required and not just a technocratic plan for improving energy efficiency and subsidizing renewable energy resources. The emergence of such revolutionary changes is unlikely to take place prior to a major meltdown of the current economic system.