The enormous cloud of uncertainty that has hung over the U.S. economy for the past five months began to dissipate last week when U.S. and allied forces attacked Iraq.</br></br>For better or worse, American households and businesses will soon know the outcome and can again make long-term plans accordingly. The invasion of Kuwait last August had produced a sort of paralysis of planning. Business executives in many industries said they were avoiding new long-term commitments wherever possible. Surveys showed that consumers cut back plans to buy new homes or cars or take vacations.</br></br>These effects, along with the real damage from soaring oil prices to consumers' pocketbooks and businesses' profits, battered an already weak U.S. economy and tipped it into a recession.</br></br>If the progress of the war and the reaction of the markets to that progress continue, there is a broad consensus that the economic outlook will have taken a decided turn for the better. The ifs remain big ones, but a swift end to the conflict would bring a double dividend to President Bush: It would insulate him from criticism over high casualties more likely from a longer war and the likely economic improvement would eliminate recession as a club in the hands of his political opponents.</br></br>Federal Reserve Chairman Alan Greenspan, who before the attack had said the economy's slide was slowing, said last week's developments should make the recession both shorter and more shallow.