For example, Trump argued that "NATO is obsolete, because it's not taking care of terror" in 2016, and he changed his word in 2017 to "It's no longer obsolete." Regarding Syria civil war issue, Trump mentioned that "Syria is not our problem" before his election, but in 2017, he takes some action to Syria and ask other nations "to join us in seeking to end the slaughter and bloodshed in Syria." Again, in 2015 he mentioned that he simply does not like export-import bank because "it is unnecessary", but in 2017 he changes his position by saying "Actually, it's a very good thing."
In my opinion, Trump often makes remarks that comes out of his mouth without filter that are very extreme, and which are very likely to bring an issue and attention. I wonder if he is even taking his presidential position serious because, from one of his interview, Trump says that he loved his previous life, and he now has "so many things going. This is more work than in [his] previous life. [he] thought it would be easier." I find this an absolute nonsense. What kind of person thinks that President life is easy? This is not a game... Trump needs to watch out these extreme remarks unless he has a clear position.