No one hear argues with Israel defending itself and Iran not friendly to Israel.
But the United States has laws and rules and standards the highest of which is the Constitution.
Franklin Roosevelt was wheeled in the House Chamber to call for a Declaration of War on December 8, 1941 and was given one by Congress.
Since then its been downhill when it comes to following that standard.
"The state of war between the United States and the Imperial Government of Japan which has thus been thrust upon the United States is hereby formally declared; and the President is hereby authorized and directed to employ the entire naval and military forces of the United States and the resources of the Government to carry on war against the Imperial Government of Japan; and, to bring the conflict to a successful termination, all the resources of the country are hereby pledged by the Congress of the United States".