What is the most important factor for increasing Iran's deterrent power? 54 thousand 810 people participated in the Fars News Agency survey on the most important factor for increasing Iran's deterrent power on the site and in the messengers. The results of the survey are as follows: Changing the nuclear doctrine: 72 percent Expanding the defense force and air defense: 11.30 percent Preventive attack on enemy military bases: 10.17 percent Increasing the range of ballistic missiles: 6.53 percent - link.