Until it is. But statements like this are why the world as a society is backsliding, countries putting up walls and isolating themselves instead of seeing the benefits of cooperation in terms of stability and economy. Just look at the economic downturn that happened in the UK when they withdrew from the EU, or how Russia was shunned, excluded and sanctioned for starting an unprovoked war.
Any benefit the US thinks they get for the policies that Trump and his ear-whisperers wants to enact will be short-term. Which is not a problem for Trump as he won't be there to see the long term consequences.