Well to be fair, if Trump hadn't removed sanctions and given Netanyahu a free run, Iran would have been more trusting of the US and come to an agreement. But Israel, under Netanyahu, sabotaged the process and used its influence among the US Congress to ensure that Iran would forever be an enemy of US. This is the first time that US has allowed another nation to dictate the course of its foreign policy against another country.
The 'used its influence' part has happened several times before, preventing US closeness with India or Russia in the past as well.
Ofcourse, none of these positions are driven by lobbying politicians in the long term, they are driven by geopolitical considerations:
US is the world hegemon and world hegemons have a problem with regional hegemons. This is why, along with India's potential threat to US as world hegemon in some future, is why US is always hostile to India and even now, US policy carefully tip-toes the line between friendship and secret backstabbing of Germany- Europe's regional hegemon.
Fucking up Nordstream literally was that - it fucked over Germany more than Russia but was IDEAL opportunity for US to cut down the Euro regional hegemon that is tactically the hardest for US to cut down, because its also NATO member and on surface, one of its strongest allies.
As such, Iran is the regional hegemon of middle east. always has been, always will be, along with Turkey. Turkey and US also have love-hate relationship and if Turkey wasn't so critical in bottling up russia in the black sea, USA would full on go all aggro on the Turks as well.
So Iran- aspiring and rising regional hegemon of ME is on natural conflict course with US and the enmity with US pyaada Israel + Isamist fascist nation-sate gives the conflict a steroid boost for volatility.
becomes a 
