Reviewed by: Patty Zakaria, University Canada West, p.zakaria@ucanwest.caA Time to Attack: The Looming Iranian Nuclear Threat discusses in depth the Iranian nuclear weapons program, Tehran's security concerns that led to nuclear proliferation, and recommendations for dealing with this security threat. The book was published prior to the 2015 Joint Comprehensive Plan of Action between P5+1 (China, France, Germany, Russia, the United Kingdom, and the United States), the European Union, and Iran, which converted Tehran's nuclear program to exclusively peaceful uses. Despite the book's somewhat hawkish title, Kroenig would prefer diplomatic solution to the crisis, but given Tehran's reluctance to give up its nuclear program, he unenthusiastically argues for the lesser evil: to strategically attack Tehran's nuclear sites. Kroenig argues that if Tehran were to acquire nuclear weapons, not only would this lead to major security threat, as well as an arms race in the region, but it would also likely create grave problem for the United States, negatively affecting the credibility of the American guarantee to its allies, particularly Israel and the Gulf states. From this perspective, the nuclear crisis falls on the shoulders of the United States to resolve.Throughout the book, Kroenig is pessimistic about containing Tehran's nuclear proliferation and resolving the crisis through diplomacy - his preferred option. After discussing why regime change, containment, sanctions, and diplomacy will fail, he offers the only solution possible. He states that regime change is very unlikely given the events following the 2009 Green Movement (calling for the removal of then-President Mahmoud Ahmadinejad), which was crushed by the government. The clerics subsequently gained much stronger hold on power. Kroenig concludes that given this situation, regime change similar to those in the Arab World through the Arab Spring will most likely not occur in Tehran. As result, using possible regime change to halt Tehran's nuclear proliferation is not possible. He further suggests that covert operations against Tehran's nuclear facilities, and the Japanese model - acquiring latent nuclear capabilities - will not stop the country from going nuclear. Having thus concluded, Kroenig then moves to his preferred method for dealing with nuclear crisis - diplomacy.The central argument of the book is to resolve the nuclear crisis diplomatically. However, Kroenig argues that diplomacy will not work because Tehran will not easily give up its nuclear program and all the benefits associated with it, and the United States does not have anything substantial to offer Tehran in exchange for giving up its program. Kroenig asks why Tehran would go through the political and economic cost of nuclear proliferation over the decades and then suddenly agree to call halt when it is a screwdriver turn away from becoming nuclear (39). …