It's not as simple as it's a trend around the world:
It’s not, as some hypothesize, related to changes in trade balance (imports vs. exports), etc. Rather, as the authors of the book explain, it’s basically due to consistent productivity growth that allows industrialized economies to turn out the same amount of goods with a smaller workforce. Now, Matthews’s post is entitled “This chart will change how you think about manufacturing” — maybe it should or shouldn’t, but it probably wouldn’t if you’d read Jim Manzi’s piece in National Affairs in 2010, which actually made the same point, with a remarkably similar chart:
What this means is that the president’s campaign plan to revive America’s labor force with manufacturing employment almost certainly won’t work — leaving aside the fact that it’s also quite poor economic policy to encourage any particular sector, but least of all one that just happens to make people feel warm and patriotic.