What is critical infrastructure? The section 1016(e) of the USA Patriot Act of 2001 (42 U.S.C. 5195c(e)) provides the definition of critical infrastructure. Presidential Policy Directive 21 (PPD-21): Critical Infrastructure Security and Resiliency identifies 16 critical infrastructure sectors at

https://obamawhitehouse.archives.gov/the-press-office/2013/02/12/presidential-policy-directive-critical-infrastructure-security-and-resil

Then describe common roles and strategies, strategic imperatives, and implementation.