Those who are astute and pay attention to world affairs understand well that today’s America is an empire, with bases, armaments, and personnel all over the world, of which it seems like there isn’t a war or rumor of war that America is not involved in directly or indirectly. That is the way it is now, but it certainly was not the way it was back then. In fact, in 1916, not only was America not directly involved in what became known as World War I, but the re-election campaign of Woodrow Wilson utilized the slogan “he kept us out of the war.”
However, on January 17, 1917, a coded message was sent to the German ambassador to Mexico, essentially indicating that Germany intended to pursue submarine warfare against America and desired an alliance with Mexico. While today’s Mexico is surely a shadow of its former self, back in 1917, it did have, relative to America, a degree of power. So then, to impress upon Mexico that Germany would aid them in the pursuit of recovering lost territories, which had become Texas, Arizona, and New Mexico, this seemed to be an alliance that might well persuade Mexico to align itself with Germany and thus be a thorn in the side of America. Further to the point, by engaging Mexico in a war with America, this would necessitate America having to take care of defending its homeland first and foremost, and therefore those military armaments that were currently being discreetly exported to the Allied cause would be considerably reduced, which might well help the German side to win that war.
The upshot of the Zimmermann telegram being intercepted is that the United States thus knew the intentions of Germany, and because of this telegram, soon declared war upon Germany, which was certainly something that Germany did not want to encourage in any way, form, or manner. Additionally, Mexico remained neutral in that conflict, so that the United States was able to exert all of its manpower and armaments in defending the allies and thus turned the tide of war in favor of those allies.
For a certainty, wars involve calculated risks, in which, had this telegram not been intercepted, perhaps the result for Germany would have been different, as the American public, for the most part, decided that they did not want to get involved in a foreign entanglement, in which, there didn’t appear to be any real reason why America should be involved, one way or another, even though American governance was clearly favoring the Allied cause. So then, this telegram simply made the call to warfare all that much more compelling to the American public and, therefore, was detrimental to Germany, which ended up being defeated in World War I.
When it comes to warfare and thus making the argument for such to the public, history tells us that there have been many instances of deceit and lies, egging a given country to that war, initiated to a great extent by those who favor such a war. In the case of the Zimmermann telegram, this, in essence, made it no longer necessary for America to pretend to be neutral and uninvolved, and thus may well have changed the outcome of that war.