by Ken Sehested
On this, my 65th birthday, I’ve made a new vow. From here on, whenever some public figure says “we need more boots on the ground” in any of our nation’s 134 theaters of conflict, I shall write them to say,
“Sir/Madame (bloodlust increasingly an equal-opportunity villainy), please come out from behind the dishonesty of your words: When you advocate for more “boots on the ground,” have the courage to say “we need more of your sons and daughters.”
If by “war” you mean “conflicts where the US is launching extensive military incursions, including drone attacks, but that are not officially ‘declared,’”  there are but five: Iraq, Afghanistan, Pakistan, Somalia and Yemen.
But if by “war” you mean countries where US Special Operations Forces are involved in combat, special missions, or advising and training foreign fighters, there are 134  of those.
Most of what Special Operations Forces do is classified. However we do know the general parameters, from the Joint Chiefs of Staff. 
“Special operations forces (SOF) are small, specially organized units manned by people carefully selected and trained to operate under physically demanding and psychologically stressful conditions to accomplish missions using modified equipment and unconventional applications of tactics against strategic and operational objectives. The unique capabilities of SOF complement those of conventional forces.”
“Joint special operations (SO) are conducted by SOF from more than one Service in hostile, denied, or politically sensitive environments to achieve military, diplomatic, informational, and/or economic objectives employing military capabilities for which there is no broad conventional force requirement. These operations may require low visibility, clandestine, or covert capabilities. SO are applicable across the range of military operations. They can be conducted independently or in conjunction with operations of conventional forces or other government agencies and may include operations through, with, or by indigenous or surrogate forces. SO differ from conventional operations in degree of physical and political risk, operational techniques, use of special equipment, modes of employment, independence from friendly support, and dependence on detailed operational intelligence and indigenous assets.”
Because of the brutal memory of European kings waging war at whim, the authors of the US Constitution inserted a “War Powers Clause,” Article I, Section 8, Clause 11, which explicitly states that “The Congress shall have Power . . . To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water. . . .” Yet the last time the US Congress made a declaration of war was in 1941 at the beginning of World War II.
Among the multiple devastations unleashed by the terrorist trauma of 11 September 2001 was the September 2002 National Security Strategy  assertion of the Bush Administration, which grants the Executive Office with virtually unlimited war-making power, including the legal justification of preemptive war.
After 11 May 1846, when President James K. Polk declared war on Mexico—claiming what now is the state of Texas to be a US possession—members of Congress questioned the action. Among them, Abraham Lincoln, then an elected representative from Illinois, wrote the following (amazingly prescient!) inquiry:
"Let me first state what I understand to be your position. It is, that if it shall become necessary, to repel invasion, the President may, without violation of the Constitution, cross the line and invade the territory of another country; and that whether such necessity exists in any given case, the President is to be the sole judge. … But Allow the President to invade a neighboring nation, whenever he shall deem it necessary to repel an invasion, and you allow him to do so, whenever he may choose to say he deems it necessary for such purpose—and allow him to make war at pleasure. … If, to-day, he should choose to say he thinks it necessary to invade Canada, to prevent the British from invading us, how could you stop him? You may say to him, 'I see no probability of the British invading us' but he will say to you 'be silent; I see it, if you don't.'” 
Every citizen ought to be required to read Wikipedia’s “Timeline of the United States military operations.  Since the end of World War II, in every year but two (1977 and 1979) records US troops engaged in hostile action outside the borders of our country.
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 Definition by Linda Bilmes (Harvard Kennedy School) and Michael Intriligator (UCLA), who defined war in a 2013 paper as “conflicts where the US is launching extensive military incursions, including drone attacks, but that are not officially ‘declared.'” —“How Many Wars Is the US Fighting Today?” in “Economics, Peace Science and Public Policy, Raul Caruso, editor-in-chief, Vol. 19, Issue 1 (May 2013), https://www.hks.harvard.edu/fs/lbilmes/paper/Drones.pdf
 “America’s Secret War in 134 Countries: The deployment of US Special Operations forces is a growing form of overseas power projection,” Nick Turse, The Nation, 14 January 2014.
 “Joint Special Operations Task Force Operations,” Joint Publication 3-05.1, 26 April 2007.