Senate approved this, right?..Right?? /s
On 13 May, the agreement was submitted by U.S. President Barack Obama for ratification in the U.S. Senate. Ratification required 67 votes in favor (out of 100 Senators). On Tuesday, 16 September 2010 the Senate Foreign Relations Committee voted 144 in favor of ratifying New START. The measure had support from three Senate Republicans: Richard Lugar of Indiana, Bob Corker of Tennessee, and Johnny Isakson of Georgia. Senator John Kerry and Secretary of State Hillary Clinton have expressed optimism that a deal on ratification was near.
Republicans in the Senate generally deferred to Jon Kyl (R-AZ), a leading conservative on defense issues, who sought a strong commitment to modernize U.S. nuclear forces, and questioned whether there was time for ratification during the lame duck session, calling for an opening of the negotiation record before a vote is held. Senator Ben Nelson (D-NE) joined Kyl in expressing skepticism over the timing of ratification,and Senator Kit Bond (R-MO) has expressed opposition.
Obama made New START ratification a priority during the 2010 post-election lame duck session of Congress, and Senators John Kerry (D-MA) and Richard Lugar (R-IN), the Democratic Chairman and senior Republican on the Senate Foreign Relations Committee, were leading supporters of the treaty.
On 22 December 2010, the U.S. Senate gave its advice and consent to ratification of the treaty, by a vote of 71 to 26 on the resolution or ratification. Thirteen Republican Senators crossed party lines to vote in favor of the resolution, along with all 56 Democratic senators and both Independent senators.
Obama signed documents completing the U.S. ratification process on 2 February 2011.
-Wikipedia
The Constitution specifies "two thirds of Senators PRESENT" (caps added). That means it takes only 34 Senators to ratify a treaty if there is a quorum.
Of course, pursuant to a treaty we never ratified, our Department of State specifies that "customary practice" is that a treaty needs only a signature of the President or an appointed representative in order to be effectively in force; IOW, it need not be ratified to be treated as law by our government.