The wicked problem: How to minimize harm caused by a dying Empire ?                 

Asimov-Seldon's Plan unfolds as follows:

establish one Foundation at the outskirts of the known Universe (Terminus)

1st Foundation 's Power base: trade, engineering, industry, diplomacy

establish the "hidden" meta-controling Foundation at the Star's End (actually University itself ;)

2nd Foundation's Power base: psychology, statistics, mental abilities

Gaia ...

The Plan is a direct application and extension of Olivaw/Demerezel's "minimalist program" defined as follows: "intervene as little as possible, but exactly when necessary, to keep history on track".

Trevize frowned. "How do you decide what is injurious, or not injurious, to humanity as a whole?"

"Precisely, sir," said Daneel. "In theory, the Zeroth Law was the answer to our problems. In practice, we could never decide. A human being is a concrete object. Injury to a person can be estimated and judged. Humanity is an abstraction."

In Foundation, the Minimalist Program is the method and the Zeroth Law is the ethical justification: both permit limited, often invisible harm or manipulation in the present to protect & preserve biosphere’s long-term survival as a Whole.