Romans 4:9-12 showed that circumcision came along after faith. Now Paul equates the circumcision of those verses with the “Law” (4:13). Law creates its own world as can be seen in this:

For the promise that he would inherit the world did not come to Abraham or to his descendants through the law but through the righteousness of faith. If it is the adherents of the law who are to be the heirs, faith is null and the promise is void. For the law brings wrath; but where there is no law, neither is there violation.

Here clearly “Law” refers to circumcision as an instance of what later came to be expressed as Torah. Paul’s point is that the promise didn’t come through Law. More important is how Paul defines that promise: it is the promise “that he would inherit the world.” This is important, for Paul saw the Jewish mission to be a world-wide task to all peoples, and instead of being concerned with the world, they were separating from that world. That is the promise for Paul. That promise came by faith.
And now Paul turns up the heat. To live by the Law, which means to raise circumcision to the top bar level and thereby elevate Jewish privilege, means to live by these:
Law creates transgression; very simply, transgression creates wrath. All you get with Law is sin and wrath. This is what commitment to the circumcision way of life will get you.
Wright contends that Paul’s eschatology is at work here: God will rule the world through Jesus the Messiah and all nations will participate in that kingdom. (This is contrary to the view by many of his fellow Jews who thought Israel would rule the world.)