Trump says he bombed Iran

[EXETER]

So we conduct war based on social media likes"?

No.  That was a Reuters/Ipsos poll. 

From their website:  "Reuters conducts public opinion polls in partnership with Ipsos  using online, probability-based panels to survey thousands of U.S. adults. They use address-based sampling to select participants, ensuring a representative sample that is weighted against Census data for demographics like age, race, and income."

On social media, the individuals select themselves to make their views known.  In a scientifically designed poll like the one being reported, the pollsters preselect the individuals to answer questions that the pollsters devise (so that everyone is responding to the same questions) and they make sure that the poll is large enough to have a statistically significant accuracy (usually to within a couple of percent) and they make sure that the sample accurately represents the demographics of the nation as a whole, and not just one particular special interest group.  

And if you are planning a new major war that is quite likely to be as long and expensive as the Iraq War, it's probably a good idea to have the legislators who are going to vote for it and the taxpayers who are going to pay for it, on board.