Violent Groups And Terrorism
We all know that violent groups or terrorists are targeting and killing small children. Children die by being "in the way" of the killing of adults by terrorists or violent groups. From the news, it seems that many innocent people are in the way of the combatants or are deliberately targeted by violent groups. These include grown men and women as well as children, if they accompany parents.
Like in Iraq or Afghanistan, many children were and are targeted by violence and war. Violent groups kill innocent children and adults.
In the U.S., the policy seems to be to protect the most vulnerable public places, and these are gov't buildings, utilities, schools, etc. However, I don't see any concentration of protection for U.S. children. With regard to them, America also need more protection against U.S. pedophiles and U.S. crazy gunmen and gun children.
Since human behavior is a combination of genes and environment ("nature and nurture"), your proposed solutions might help the environmentally induced aggression, but not our genetically induced aggression. Therefore, aggression will always be with us, not matter what environment is established.
However, considering the latter as a way to at least reduce aggression somewhat, consider that asocial behavior of all kinds is a consequence of the combination of ignorance, aggression, and greed. Formal education partially helps - employment partially helps - good parenting helps, but nobody pays any attention to that source of our problems. Thus, what you propose are only partial solutions.
As for "good government", that would help all three problems indirectly by promoting employment, education, good parenting, etc., but that concept must be translated into specific programs to be meaningful.
Violence can be defined as "the murder of innocents", i.e., non-military, non-police, and non-politicians. The Army is used by the government to protect the general population from foreign and domestic aggressors.
Armies and police can defend the country against violence, but are ineffective against isolated attacks. Outside the country, an army can assist to defeat terrorism, but cannot accomplish that alone because terrorists are not found in armies. The only way to defeat terrorism and violence is to assist police and intelligence. However, it will take a long time.
These groups can survive longer if they become immune within a country. That is why it is important to bring them to justice. The deaths and the property losses after attacks cannot be restored completely no matter how much money other countries send.
We certainly can defeat violence and terrorism if we spend much more time, give justice, and create awareness on peace - as part of a long term goal. Whether or not we will be willing to make these sacrifices to achieve these objectives is indeterminable at this time.