Recent chronology bears this out.
When President Obama took office in 2009, Iran was under several UN sanctions conditioned on its suspension of all uranium enrichment-related and reprocessing activities. At the time, Iran had 1,200 kilos of low-enriched uranium at its Natanz facility.
Mr. Obama chose to engage the Islamic regime, believing that an extended hand would yield better results than threats. He reasoned that a new US approach would be welcomed by Tehran because it was a complete change from the Bush administration.
However, the radicals ruling Iran saw this extended hand as weakness. They engaged the Obama administration while enriching uranium beyond the benign 3.5 percent level, as it had been limited to for many years, to the 20 percent level. While that is not a high enough enrichment level for a nuclear weapon, it is high enough to get to bomb-grade very quickly – in a matter of weeks if Tehran decides to do so.
Early in 2010, Obama, realizing his defeat in the negotiation phase, moved to a sanctions phase. But instead of the crippling sanctions he had promised, he started step-by-step sanctions that Iran’s clerics saw as further proof of America’s inability to stop Iran, which emboldened them to speed up their program.