Earlier quoted context omitted.
Can they be allies with neither? They are trying to improve relations with the EU and, most importantly, are members of NATO (where the US is also a member).
Economically not really. China and the USA are the top economies, and China is only going to get more economically powerful, alignment with one or the other in trade at least is inevitable. The EU will be making similar decisions to Canada, and I doubt Canada is going to detach from Europe.
They're also staring down a demographic crash, soon (10 - 15% drop with 25% of the remaining polution over 65).
They are basically at their peak right now.