Obama is taking a huge risk that his diplomacy will work out for the best in the end. I believe taking that risk is reckless and irresponsible. We absolutely should have put war on the table and dictated the terms to the Iranians or else. For Gods sakes the Iranian leadership goal is to bring down Israel and the United States. We know this because they say so frequently.
Did negotiating with North Korea keep them from cheating and getting the bomb?
There is absolutely no reason to trust we can verify anything, short of what we did in Iraq to Saddam. The Iranians wouldn't even concede that their ambition is to get a nuclear weapons.