The world has three choices. We can allow Iran to develop nuclear weapons, with all of the terrorist access that will create, allowing deployment anywhere in the world without the use of rockets or missiles. We can go to war with Iran, striking the facilities we believe house their nuclear research programs, with all of the death, destruction, and radicalization that entails. Lastly, we can use economic and diplomatic sanctions to force Iran back to the table for honest negotiations to end their pursuit of nuclear weapons. There isn't a fourth option.
Which option do the Democrats want to take? Are they seriously considering the first option? If so, then they have no claim to understanding global security. Barack Obama offered the rather silly notion that we should negotiate directly with a nation with whom we have no diplomatic relations, primarily because they issue genocidal threats against our ally and conduct low-level war against us through their terrorist proxies.