Donald Trump has recently pulled US out of the Iran Nuclear deal:
US President Donald Trump says he will withdraw the US from an Obama-era nuclear agreement with Iran.
Calling it "decaying and rotten", he said the deal was "an embarrassment" to him "as a citizen".
Going against advice from European allies, he said he would reimpose economic sanctions that were waived when the deal was signed in 2015.
I find it concerning that the US and EU have opposite positions when it comes to such an important deal.
Question: Why aredid the US and EUUSA want to pull out of sync when it comes to Iran Nuclearthe nuclear deal with Iran?
This question and its answers explain about the Iran nuclear deal weaknesses and why it is frowned upon by the US and Russia. These answers provide a justification for Trump's recent action, but do not seem to explain the EU's (European allies) position on this matter.
So, my question can be reduced to: since the nuclear deal seems to have so many weaknesses, why are EU leaders "determined to preserve" the deal?