This might mean its own thread, but the Hostage Crisis almost became a war. Even though Mr. Peanut rejected bombing Iran's oil refineries or seizing Kharg Island via Marine amphib assault, as his administration wound down and the talks to free the hostages seemed to go nowhere, he warned the Iranians that they'd better come to a deal or face the wrath of Ronald Reagan, who had gone on record for stronger action, and calling the Iranians "barbarians and kidnappers." There were usually two carrier groups on station in the Arabian Sea until the release, and it was understood that Bahrain and Oman would allow USAF squadrons to base there if necessary. Had the hostages not been released when they were (20 Jan 81), Reagan likely would've issued some firm ultimatium, and the lead flies, the bombs fall, and things go from there.
Either carter decides to be bold, or the crisis is unresolved by Regan. What happens? Do the Iranians back down?