Your notion of "manufacturing" needs to be expanded broadly to include the making/provision of valuable intangibles, like services, or of intellectual property. Unceasingly producing valuable things of any kind, be they edible/wearable, etc., or not, is the way to create wealth.
May I jump in here and point out that tangibles carry the added value within themselves, i.e., the added value in these tangibles can be sold now or stored for later sale. Services, however, either get sold or they don't.
Two examples: I had a friend who was a medical doctor, his brother had a lucrative distributorship. Essentially, they both made equal money in good times. But there was a problem. Both men were raging alcoholics! When the Dr. was out of the office, he made no money. When his brother was laid up drunk, his managers continued to move product and make dollars.
Another example: I once had an interest in a broadcast facility. There are "x" number of spots that can be sold for cash in a day. If those spots are not sold, you can NEVER recoup the loss because the day is gone after 24 short hours.
Now, if you are talking about "intellectual property" - patents, etc. you have a point except for the fact that the people who are in the lab/factory/production facility are most likely to be the ones who come up with the great ideas. Also, it is arrogant to imagine that foreigners can't and won't develop intellectual property that is the equal of ours.
I guess my problem is I grew up in the 1950's and watched all those documentaries with the solemn-voiced announcers talking about "the arsenal of democracy" and showing sweating workers with sparks flying everywhere and "Rosie the Riveter" types tightening bolts on tanks. We don't have that and I can't see how that bodes well for our national defense. Some folks say that high-tech defense capabilities eliminate all that but I don't buy it. It looks to me like the situation in Iraq is being fought the way all our wars have - hillbillies, college boys, and urban apartment dwellers with rifles are doing the work. May God bless them; I hope we can continue to give them the tools they need.