This was my response to a short paper that my daughter wrote.
My inclination is to limit the phrase “asymmetric warfare” to situations where one force (group or nation) in a conflict is clearly inferior to their opponent. I would include attacks by a nation like Iran (their Quds Force) against the US military in Iraq: the Iranians provided IEDs to Shiite militias, resulting in many US casualties in the years following the US invasion of Iraq.
I don’t believe that cyber warfare between the US and China is asymmetric warfare: it depends on whether you consider China to be clearly inferior in its military or technological power. I also doubt that cyber attacks from Russia are asymmetric warfare. One question is whether the Chinese or Russian attacks are state-sponsored, or if they are perpetrated by criminal gangs. In general, I tend to see China and Russia as on par with the US in terms of their military capabilities; or at least I contend that the US is not overwhelmingly more powerful than those countries. The US has a more powerful military, but we are constrained by our political leadership. China or Russia can commit military forces without having to worry about public opinion: their governments control their news media, so they can shape public opinion in their nations. The US can defend itself, but we are a war-weary nation: the US will not be able to project power in Europe, Asia, or the Middle East given our current political situation.
I do not believe that attacks by the North Koreans on the South represent asymmetric warfare: these nations have comparable military forces. A North Korean attack on the US would be asymmetric.
Terrorism has become the preeminent form of asymmetric warfare in the 21st century in my opinion, because of attacks on civilians by the PLO, Al Qaeda, Hamas (and several other groups), and more recently ISIS. I am unsure about the limits of terrorism. Is it terrorism to attack soldiers when they are garrisoned in a colony or in a foreign country? In the Zionist struggle for the independence of Israel, at least one group assassinated British soldiers; was that terrorism? What if a government has accepted the presence of foreign soldiers; would attacks on those soldiers be considered terrorism?
David Skeen 
From trey smith for David Skeen.
Sent from my iPhone
Begin forwarded message:
> From: “Trey Smith” > Date: October 16, 2015 at 9:18:32 PM EDT > To: “‘Susan'” , “‘Elizabeth Smith'” > Subject: RE: [New post] A few thoughts on asymmetric warfare > > My definition of asymmetric warfare is a little different and probably not the proper one. > > I define it as the use of non-conventional (or at least new and unused) weapons and tactics to overcome the superiority of a military in a certain area. > > For example, the US Navy has an overwhelming advantage in aircraft carriers and I don’t believe any country, including China, will ever overcome that gap. However, I do believe the best military minds in China, Iran, Russia, North Korea, etc. are trying to device means to make the carrier obsolete. For all its power, the aircraft carrier is a mighty big target and taking out even one carrier would be a huge victory for an opponent. > > I imagine any US admiral commanding a task force involving carriers gets mighty nervous when small, fast, highly maneuverable boats approach. And I imagine most of our planning for the next conflict involves trying to guess, and then counteract, what new strategy our opponents might use. > > I think the same thing applies to air forces. The Israelis won the 6-Day War in 1967 using their Air Force. The Egyptians almost won the Yom Kippur War in 1973 by using Russian SAMs to make the successful tactics of 1967 obsolete. > > I realize that part of what I am describing is simply the ongoing evolution of arms and tactics but that is my civilian’s definition of asymmetrical warfare. > > Love, > > Dad > > > > From: Susan [mailto:c-smithsw@comcast.net] > Sent: Friday, October 16, 2015 7:06 PM > To: Elizabeth Smith ; Trey Smith > Subject: Fwd: [New post] A few thoughts on asymmetric warfare > > FYI > > Sent from my iPhone > > Begin forwarded message: > > From: David Skeen > Date: October 16, 2015 at 5:41:02 PM EDT > To: c-smithsw@comcast.net > Subject: [New post] A few thoughts on asymmetric warfare > Reply-To: “David Skeen” > > davidlskeen posted: “This was my response to a short paper that my daughter wrote. My inclination is to limit the phrase “asymmetric warfare” to situations where one force (group or nation) in a conflict is clearly inferior to their opponent. I would include attacks by ” >
Thanks, Trey; interesting perspective. I had not considered asymmetric in terms of one part of a conflict, or one theater of operations. The scenarios you describe would fit the term. Also efforts by a US enemy to knock out satellite communications would be another form of asymmetric warfare, as would an EMP attack.