Despite Fornari's theory that man's altruistic desire for self-sacrifice for a noble cause is a contributing factor towards war,few wars have originated from a desire for war among the general populace.  Far more often the general population has been reluctantly drawn into war by its rulers. One psychological theory that looks at the leaders is advanced by Maurice Walsh.  He argues the general populace is more neutral towards war and wars occur when leaders with a psychologically abnormal disregard for human life are placed into power. War is caused by leaders who seek war such as Napoleon and Hitler . Such leaders most often come to power in times of crisis when the populace opts for a decisive leader, who then leads the nation to war.
"Although the mean annual opioid analgesic overdose mortality rate was lower in states with medical cannabis laws compared with states without such laws, the findings of our secondary analyses deserve further consideration. State-specific characteristics, such as trends in attitudes or health behaviors, may explain variation in medical cannabis laws and opioid analgesic overdose mortality, and we found some evidence that differences in these characteristics contributed to our findings. When including state-specific linear time trends in regression models, which are used to adjust for hard-to-measure confounders that change over time, the association between laws and opioid analgesic overdose mortality weakened. In contrast, we did not find evidence that states that passed medical cannabis laws had different overdose mortality rates in years prior to law passage, providing a temporal link between laws and changes in opioid analgesic overdose mortality. In addition, we did not find evidence that laws were associated with differences in mortality rates for unrelated conditions (heart disease and septicemia), suggesting that differences in opioid analgesic overdose mortality cannot be explained by broader changes in health. In summary, although we found a lower mean annual rate of opioid analgesic mortality in states with medical cannabis laws, a direct causal link cannot be established."