On page 245 of Paul and the Gentiles, Terence Donaldson says that certain consequences flow from N.T. Wright's analysis, which (in this case) states that (in Pauline thought) God gave the Torah to Israel in order to concentrate sin into that one nation, thereby allowing Israel's representative to be the one to deal with sin once and for all:
"Since Christ identifies first with Israel, the saving benefits made possible in his death and resurrection pertain in the first instance to Israel. Thus it is quite to be expected that we should find the Jewish Christian remnant perceived as the primary beneficiary of Christ's ministry, and the means by which those benefits are extended to the Gentiles. Further, since Israel functions as a representative sample of Adam's family as a whole, it is also to be expected that what Christ accomplishes for 'the circumcision' is applicable in principle and available on the same terms to everyone, Jew and Gentile alike. This further explains why it was possible for Paul to formulate his soteriology in ways that move directly from Christ to 'all,' with no explicit mention of the Jewish middle term. As the representative individual of the representative family, Christ is the representative of all (see 2 Cor 5:14). Because of the particular role assigned to Israel, Christ's redemption of Israel is at the same time and on the same terms the redemption of the whole human family. When it suits his purposes, Paul can pass over the intervening step in silence."
I can't say that this makes a great deal of sense to me, but maybe my writing about it can make things clearer (to myself, at least). The issue, it seems to me, is this: If God gave the Torah specifically to Israel, and Christ died to redeem people from the curse of the Torah, then does that mean that he died for the Jews alone, and not for the Gentiles? Donaldson says that, in Wright's scenario, the answer is no, for three reasons. First, Israel is a representative sample of the entire human race. The idea here may be, at least partially, that Israel is a microcosm of what all of humanity experiences, namely, failure to live up to God's demands. Second, Christ is the representative, not just of Israel, but of all of humanity. Third, Israel had the redemptive role of correcting the sin of Adam, a role that Christ assumed for himself after Israel's failure. For these reasons, the argument appears to run, Paul does not always mention Israel in his discussions about sin, the law, redemption, etc., portraying these instead as larger human concerns, even though Israel played a significant role in his thought on these matters.
There may be something to all that, but where Wright frustrated me was that I continually wondered what the evidence was for his scenario----of Christ dealing with Israel's sin, and the result of that being blessing for humanity. Wright's answer was that Paul is not always explicit and that we can presume that Paul assumed certain Jewish notions of his day----such as, for example, that Israel was representative of all of humanity and had a redemptive role for it. I have a hard time with an approach of claiming to read Paul's mind, especially in cases where Paul is not explicit. Granted, maybe Paul did assume those things, but did he apply them the way that Wright thinks that he did? How can we know for sure, if Paul does not tell us?