What warnings did ex-US intel chief Gabbard give Trump ahead of Iran war?

US President Donald Trump ignored several high-level warnings from ex-US intelligence chief Tulsi Gabbard before starting the Iran war, WSJ reported. Trump was warned that killing Iran's Supreme Leader Ali Khamenei would bring in a hardline regime more inclined to pursue nuclear arms. Moreover, Iran would immediately choke off the Hormuz Strait and also target US military assets in Gulf.