Brent Scowcroft, the former national security adviser for two Republican presidents and considered a Washington sage, said he supports the Obama administration's nuclear deal with Iran and pressed Congress to support it.

Mr. Scowcroft, who worked for Presidents Gerald Ford and George H.W. Bush, wrote an op-ed in the Washington Post's Sunday edition in which he urged lawmakers not to confuse opposition to the agreement with support for Israel. He also likened the deal to agreements Presidents Richard Nixon made with China...