"The doer is always conscienceless; no one has a conscience except the spectator." - Goethe
These few words from the great German poet have what lawyers like to call "explanatory value." We spectators tend to huff and puff about broken campaign promises from our politicians. How can they renounce or ignore what they so earnestly promised when seeking our votes? The reality is, how can they not?
No doubt you've noticed that it's only when their faction is out of power that politicians embrace a set of appealing "principles," which they cast aside upon attaining or regaining ruling power. This is confusing to people ignorant of the fact that politicians, while preaching sentimental or program politics, actually do not believe their own words. The born politician, like everybody, has convictions that are dear to him as an individual - a private person, if you will - but does not feel bound by them when performing as an officeholder. If he did, he would soon be seeking another profession.
How many American presidents have promised to keep us out of war while actually plotting how to get us into one? Let's see, there was Woodrow Wilson, who won reelection in 1916 behind the campaign slogan "He kept us out of [the] war," and then, safely into a second term, did everything he could to get us into it. The ostensible reason for the switcheroo was to "make the world safe for democracy." The real reason was to further American imperial ambitions.
Franklin Delano Roosevelt also stated his desire for peace by using a similar slogan, "I will keep us out of war," while instituting a series of initiatives involving the United States in World War II before there was a declaration of war by Congress. First came the Conscription Bill, which the president and his people said was only for our own defense and that the men being drafted wouldn't be forced to serve more than a year and wouldn't be sent outside the Western Hemisphere. Then there was the Lend-Lease Bill, peddled as a way to prevent us from being sucked into another world war while actually giving the president the power to distribute American arms to Britain and other favored nations - which meant, of course, that we were then de facto actually involved in the war. You get the picture.