There is a camaraderie that happens when people cooperate in a worthy cause, like pulling out of an economic slump. That's unlike the nationalist's feeling of superiority which can justify ignoring the welfare of the global community to pursue selfish interests.
On more of an individual level sure. just seems easier to motivate people if you first get them to identify as a group then motivate them to support the group.
Team sports, Olympics, for productivity we get taught to motivate people as teams.
Sometimes a team is superior. That motivates the other teams towards better performance. There's good competition and bad competition. It is up to the leaders to make sure bad competition is not allowed.