USA has not, IMO, failed to make war on Iran. Israel s/b pleased.
The sanctions against Iran escalated by USA since the multi-party agreement are themselves acts of war in my book. Causing starvation, interfering with importation of medicine, , all that sort of thing is warfare by economic means. Seems to me.
The cyber warfare by both sides also seems warfare.
International law may not have caught up with these forms of warfare, but nowadays, nations are not attending much to international law of war, are they?