It has nothing to do with being left or right but with being pragmatic. If you think, Poland alone can assert her interests in a globalized world, you're delusional. You cannot vote facts away.
A strong Europe is Polands only hope. You can only reach your maximum performance, when you play among your own. The European countries share the same borders, have a common market and the same currency.
America cannot be a partner for Poland because it plays in a different league. An alliance will always be a one-way alliance as will be a "friendship". To America you're a lap dog. One of those countries they can use.