Did the USA need NATO protection? No. NATO is an intergovernmental military alliance, there to provide collective defense against external threats to Alliance members. It's role is primarily for deterrence. Yes, Turkey is home to NATO's second largest Armed Forces after the US Armed Forces and can handle Syria on its own. However, NATO handles problems against member States collectively. If anything, Turkey isn't begging for support or getting free protection. It has been contributing to NATO since the Korean war. It has also been footing a portion of NATO's bills since the Korean war. Turkey has supported all NATO missions to date and has also provided military assets to NATO. These are the facts. Not populism fueled misconceptions.
Singapore arrests man who tried to join ISIS (Reuters)
from the article: NATO chief pledges to defend Turkey against Syria