WASHINGTON—With U.S. troops fighting pitched battles on two Iraqi fronts last night, a question dismissed by the White House as naïve last summer has gained increasing currency this spring. Is this George Bush's Vietnam? The charge was made in a Monday speech by one of the country's most polarizing politicians, Massachusetts Senator Ted Kennedy, the 42-year veteran of Congress. He struck a chord in this nation and the question was being put to the U.S. administrator in Iraq, Paul Bremer, on network television yesterday while most Americans were still digesting the latest Iraqi battles over their morning coffee. By...