His failure to modify the guaranty may be considered another rejection of the "self-denying covenant" and a final decision to insist on the affirmative form of guaranty in spite of the unanimous opposition of his American colleagues.
In view of what later occurred a very definite conclusion may be reached concerning the President's rejection of the proposed substitute for his guaranty.

Article 10 was from the first the storm center of opposition to the report of the Commission on the League of Nations and the chief cause for refusal of consent to the ratification of the Treaty of Versailles by the Senate of the United States.

The vulnerable nature of the provision, which had been so plainly pointed out to the President before the Covenant was submitted to the Commission, invited attack.

If he had listened to the advice of his colleagues, in fact if he had listened to any American who expressed an opinion on the subject, the Treaty would probably have obtained the speedy approval of the Senate.
There would have been opposition from those inimical to the United States entering any international organization, but it would have been insufficient to prevent ratification of the Treaty.
As it was, the President's unalterable determination to have his form of guaranty in the Covenant, in which he was successful, and his firm refusal to modify it in any substantial way resulted in strengthening the opponents to the League to such an extent that they were able to prevent the Treaty from obtaining the necessary consent of two thirds of the Senators.
The sincerity of Mr.Wilson's belief in the absolute necessity of the guaranty, which he proposed, to the preservation of international peace cannot be doubted.

While his advisers were practically unanimous in the opinion that policy, as well as principle, demanded a change in the guaranty, he clung tenaciously to the affirmative form.