A federal judge questioned Wednesday what was behind the government’s decision to dramatically reduce the proposed size of a nationwide stop-smoking program, one of the penalties recommended in a racketeering suit against cigarette makers.

The government asked U.S. District Judge Gladys Kessler on Tuesday to require the companies to fund a five-year, $10 billion program — a fraction of the 25-year, $130 billion program suggested by government witness Michael C. Fiore, a University of Wisconsin medical professor.