The correct answer to this open question is the following.
Security is an essential element of society because a good security system would prove the proper protection for the citizens against any internal or external threat.
Let's set the example of the September 11 terrorist attacks over many places in the United States. After those attacks, President George W. Bush ordered the creation of FEMA, the Federal Emergency Management Agency, and later the Patriot Act. He considered that these were proper pieces of legislation to protect the United States against terrorism
On the international side, we have the example of NATO, the North Atlantic Treaty Organization
Article 5 of the NATO Treaty promises the mutual defense of member nations: "Restore and maintain the security of the North Atlantic area."(April 4, 1949).
The North Atlantic Treaty Organization is a key strategic agreement, a military agreement indeed, signed by 30 European and North American countries to protect each other in case of military aggression or intervention.
The headquarters of NATO are located in the European city of Brussels, in Belgium. Among the countries that are part of NATO are the United States, Great Britain, Canada, France, Belgium, and Spain.