What did Stalin do while western powers rebuilt Germany?

In June 1948, Stalin instituted the Berlin Blockade, one of the first major crises of the Cold War, preventing food, materials, and supplies from arriving in West Berlin. The United States and several other countries responded with the massive “Berlin airlift,” supplying West Berlin with food and other provisions.

Explanation:

an interest group is an organization whose members share common concerns, and try to influence government policies that impact those concerns. elected officials frequently complain about the influence of "special interests" on american politics.