Biden is arming Iran with his clustercrap nuclear deal so that they can supply Russia, Hamas, Hezbollah and the Houthis. If anyone starts WW3 it will be Biden by December 31 or whoever they replace him with.
Trump if elected, will go to war with Iran. Iran has vowed to kill Trump for the assassination of Qasem Soleimani. Trump will want to remove that threat. Just like George Bush II went to war with Iraq because Saddam Hussein vowed to kill George Bush I for the Gulf War.