Tim why don't you ever first read the passage and think about what its author was talking about before you post?
Paul is talking about Gentile circumcision and about two groups of people:
1. Those Jews who today we commonly refer to as "Judaizers", who were insisting that all Gentiles in Christ must be circumcised; and
2. Those Jews (the circumcision) who did not follow the rule of the Judaizers, but followed Paul's statement regarding circumcision, who together with the Gentiles in Christ Paul called "The Israel of God".
11 See in what large letters I write to you with my hand.
12 As many as desire to look well in the flesh, these compel you to be circumcised; only lest they should suffer persecution for the cross of Christ.
13 For they themselves, having been circumcised, do not even keep the Law, but they desire you to be circumcised so that they may boast in your flesh.
14 But may it never be for me to boast, except in the cross of our Lord Jesus Christ, by whom the world is crucified to me, and I to the world.
15 For in Christ Jesus neither circumcision has any strength, nor uncircumcision, but a new creation.
16 And as many as walk according to this rule, peace and mercy be upon them and upon the Israel of God.
17 For the rest, let no one give troubles to me, for I bear in my body the brands of the Lord Jesus.
18 Brothers, the grace of our Lord Jesus Christ be with your spirit. Amen.