That 2% goal was agreed in 2002 according to most sources.
What happened 2003? Exactly. 2nd Gulf War, invasion of Iraq. More "defense spending"..
Not even the french followed the US that time. "Weapons of Mass Destruction" [knocked out]
Why a "denfense spending" that is used on invading random countries is not a very popular idea in Germany should be kinda obvious.
Yup, and honestly the US has never wanted Germany to actually spend 2% on armament. That would make the US entirely unnecessary in Europe's defence planning. Germany wouldn't know where to put all that money, and the military would dwarf that of Russia. It would look ridiculous, and people would panic about a 4rd Reich.