The cost is still small comparing to the possibility of IP theft once the foreign countries figured out the secret sauce and start to make your products using your secret sauce and sell them cheap to undercut you. US and western companies need to think longer term instead of always focusing on cost all the time and choose their production partners wisely.
Bringing manufacturing home is a good idea as long as you can manage the environment aspect of it. One of the main reasons why manufacturing is so much outsourced nowadays is that some of the steps in the manufacturing process is still highly polluting and/or damaging to the workers' health. Once those processes are outsourced, it's those foreign countries' problem and the company can answer to those environmental groups much easier. So it's no easy feat but then the IP theft and the loss of skilled workers in the manufacturing sector in the US and the West is troubling too.
There is no "secret sauce" to shoe making