1775 - American Revolutionary War. Disputed. The British may have fired first, but in any case their ridiculous taxes were enough of a provocation.
1801 - First Barbary War. American ships held by state-sponsored Barbary pirates without American provocation.
1812 - War of 1812. Started by Britain. The British captured American sailors without provocation on our part.
1846 - Mexican-American War. American territory invaded by Mexico without American provocation.
1861 - American Civil War. Confederate States of America fired the first shots on Fort Sumter without provocation.
1898 - Spanish-American War. Spain threatened American interests in Cuba and may have had a role in the destruction of the USS Maine (ACR-1). No overt American provocation.
1917 - World War One (American entry). German naval forces continued to attack and sink neutral American merchant ships. No American provocation (America was supplying both sides equally)
1941 - World War Two (American entry). Japanese naval forces executed aerial attack on the US naval base at Pearl Harbor. No significant American military provocation.
1950 - Korean War. Disputed. North Korea threatens South Korea (and the rest of the region) with a hostile communist conquest. America intervenes as part of a UN mission.No direct American provocation.
1964 - Vietnam War (Gulf of Tonkin incident). Disputed. North Vietnamese naval forces launch attack American destroyer USS Maddox (DD-731) American intervention therefore may have been justified. I'm not going to argue about this one, just throwing it out there.
1983, 1989, and 1994-1995 - American interventions in Grenada, Panama, and Haiti respectively. American interests threatened without American provocation.
1991 - Operation Desert Storm. American energy supply seriously threatened by Iraqi invasion of Kuwait and threatened invasion of Saudi Arabia. No American provocation.
2001 - Operation Enduring Freedom. American civil and military infrastructure attacked by al-Qaeda suicide attackers based in Afghanistan on September 11, 2001. No American provocation.
"My point is, however, that I think Americans started to try hacking the Chinese first, to "keep the peace" of course. Not saying that's a problem, but you can hardly blame them from trying to hack you too. So that's what I meant with fighting back. Hacking back in this case."
You're making the wild, baseless speculation that America hacked China first. In effect, you were assuming that America was the aggressor.