The Pentagon has ordered about 1,500 active-duty soldiers to be ready in case of a possible deployment to Minnesota, where federal authorities have been conducting a massive immigration enforcement operation. Two defense officials, who spoke on condition of anonymity to discuss sensitive military plans, said Sunday that two infantry battalions of the Army’s 11th Airborne Division have been given prepare-to-deploy orders if President Donald Trump invokes the 19th century Insurrection Act. The president suggested he might use it but then later walked back the threat.