Quoting from a theological dictionary:
God's intention and desire to bless humanity is a central focus of his covenant relationships. For this reason, the concept of blessing pervades the biblical record. Two distinct ideas are present. First, a blessing was a public declaration of a favored status with God. Second, the blessing endowed power for prosperity and success. In all cases, the blessing served as a guide and motivation to pursue a course of life within the blessing.
Considering the prosperity in the US, especially relative to the rest of the world, for the past century or two, I'd say this fits. Although I do feel that we are in the process of losing that status, and we will watch the demise of this great nation.
We're (the US) one of Israel's strongest and most powerful allies (sans the weakened support by the current administration). Your "Israel" comment is buffoonery.
As an aside, the day our support for Israel stops, so will our existence as a "blessed" nation. (Replace "blessed" with any positive adjective ascribable to our "greatest nation on God's green earth").