President Obama is preparing to cement his legacy with several big changes in U.S. nuclear-weapons policy—and he’s willing to go around the GOP-controlled Congress to do it.

“Top administration officials,” according to Josh Rogin of the Washington Post, “briefed lawmakers and congressional staffers … about President Obama’s decision to push for … U.N. action this September, to coincide with the 20th anniversary of the Comprehensive Test Ban Treaty.” “U.N. action” could include a Security Council resolution calling for more states to ratify the CTBT, and for the treaty’s current signatories to meet their commitments.

The problem is that the administration has chosen yet again to circumvent the legislative branch. Regardless of what Obama’s advisors may say in public, bringing the nuclear-testing issue to the Security Council is in effect a way to short-circuit a far more arduous process in the Senate that the White House would be likely to lose.

This is not illegal—President Obama has the power to unilaterally represent the United States at the United Nations. But it is emblematic of the president’s broader disdain for the other branches of government, and it has congressional Republicans fuming.

In an angry letter, Senate Foreign Relations Committee Chairman Bob Corker wrote that “The U.S. Constitution clearly provides the Senate—not the United Nations—the right to the provision of advice and consent for the ratification of any treaty, including the ability to identify when a treaty or the application of the provisions contained in a treaty is not in the U.S. interest. Your administration seeks to ignore the judgment made by a co-equal branch of government regarding the treaty.”

Senator Corker disagrees with much of what the Obama administration is proposing on the merits. He, along with many of his Republican colleagues, believes that promoting ratification of the CTBT at this time would be a mistake and tie the hands of a future administration. Reasonable people can disagree with the technicalities and particulars of U.S. nuclear-weapons policy. What is less complicated is Corker’s assertion that President Obama is once again refusing to engage the legislative branch on a vital issue.

To Senator Corker and a lot of other lawmakers, Obama’s nuclear gambit is just the latest example of him depicting Congress as a bunch of babies who are too immature to do something that is politically difficult but strategically wise for the United States. Even the most partisan Obama supporter would be hard-pressed not to concede this point, because the trend over the past seven and a half years has been so clear: on immigration, climate change, Guantanamo, gun rights, and now nuclear testing, President Obama has decided to embrace unilateral action when the legislative branch doesn’t provide him the authority he is seeking.

All presidents, of course, use their unilateral authority through executive orders and proclamations. But President Obama’s use of the tactic surpasses even that of his predecessor George W. Bush, whom Democrats used to castigate for creating new laws without congressional input or buy-in. In the case of nuclear weapons, President Obama doesn’t even need an executive order.

If Obama gets the Security Council resolution he wants, it will be largely symbolic in the grand scheme of things. In fact, the resolution that the administration is purportedly thinking about would be the equivalent of a “sense of the Senate” resolution: it would put the chamber on the record, but it wouldn’t formulate policy.

Obama’s skirting the Senate on a nuclear treaty, however, is a continuation of what is obviously contempt for a Republican-dominated Congress that has filibustered legislation, blocked judicial nominees, and placed ideological riders in spending bills for the past seven years. Just like Congress, Obama is leveraging his power to the extreme.

Daniel R. DePetris is an analyst at Wikistrat, Inc., a geostrategic consulting firm, and a freelance researcher. He has also written for CNN.com, Small Wars Journal, and the Diplomat.