Sad to say, war is nothing new to our species, anonymous. In fact, the Johto-Kanto war (which was really less between Johto and Kanto and more between a number of different kingdoms that occupied the same space, as well as Sinnoh, back in the feudal era) and the war Surge had fought in are just two of a long, long history for humankind. World peace has only really been a recent thing, decided upon after the destruction of most of Western civilization.
Or, well, that’s a simplified explanation. In truth, world peace came about as a result of nearly a century of war and political turmoil, beginning with the second World War (perhaps the first, depending on whom you ask) and ending when the Cold War abruptly turned hot in the late 80s and early 90s. From what I understand, Lt. Surge fought in the Final War somewhere in the region of Fajir when the so-called “warning shot” was fired. That warning shot being, of course, the attack that flattened much of the American West and rendered Orre, which sat at the southwest corner of it, virtually uninhabitable by wild pokémon. (To this day, no one is quite certain what launched said attack. The media called it a conventional weapon of some sort, but researchers have noted that it looked suspiciously like the signature attack of a legendary rumored to live in Siberia—a hypothesis that’s only worth noting because there had been one other documented instance of that attack in use, during the Tunguska event in 1908. The only other viable theory is that the attack was launched by an American legendary, which—according to the conspiracy theorists, anyway—was responding to nuclear testing.)
In any case, thanks to the devastation rendered by the warning shot, world leaders decided to put aside politics once and for all and work towards establishing peace—at least on a national level, anyway. The downside of the swiftness of this agreement is that not that many people agreed to set aside differences they may have with others, which is why these days, the threats to our world come in the form of private organizations that have realized (also thanks to the warning shot) that modern technology has advanced just enough to allow for the weaponization of legendary pokémon. Such as, for example, Team Rocket.
In other words, anonymous, it’s my understanding that Lt. Surge fought in the last of a very long history of wars, which only ended because someone had very likely figured out how to harness the power of the legendaries. (Well, again. There are stories of nations doing this in ancient history, but our relationship with pokémon back then was far, far stronger than it is now.) But that’s about all I know, as I have very little interest in listening to the man’s war stories beyond understanding that such level of violence must never be repeated.