Former congressman William Broomfield of Michigan, who as the longtime ranking Republican of the House Foreign Affairs Committee was a prominent GOP voice on foreign policy during his 36 years in Congress, died Feb. 20 in Kensington, Md., where he resided. He was 96.

The Associated Press reported his death, citing a statement from his family. The cause was not reported.

Mr. Broomfield was elected in 1956 to the House of Representatives and stepped down in 1993 after 18 terms, a tenure that made him, by the time of his retirement, one of the two most senior House Republicans. (The other was then-Minority Leader Robert H. Michel of Illinois, who also was elected in 1956.)

Mr. Broomfield represented Oakland County, containing some of the most prosperous suburbs of Detroit, and served for his entire time in Congress in the minority. He exercised his greatest influence as ranking Republican for 18 years on the Foreign Affairs Committee, which he joined in 1961.

The Almanac of American Politics called him the “chief House spokesman for the Reagan and Bush Administrations on one issue after another: aid to the Nicaraguan contras and arms control, El Salvador and Eastern Europe, Grenada and the Gulf War.”

A notable exception was his vote in 1986 to impose sanctions on the apartheid regime of South Africa, a measure that President Ronald Reagan vetoed. Congress ultimately overrode the veto.

Mr. Broomfield participated in hearings investigating the Iran-contra affair, in which U.S. officials during the Reagan administration secretly sold arms to Iran and diverted proceeds to the Nicaraguan contras fighting their country’s socialist government.

The final congressional report on the matter, in 1987, found that “fundamental processes of governance were disregarded and the rule of law was subverted,” and that Reagan carried “the ultimate responsibility” for malfeasance by his staff.

Mr. Broomfield was among the Republican signatories of a dissenting report, which called the majority’s finding “hysterical.”

“President Reagan and his staff made mistakes in the Iran-contra affair,” the report declared. “The bottom line, however, is that the mistakes . . . were just that, mistakes in judgment, and nothing more. There was no constitutional crisis, no systematic disrespect for the ‘rule of law,’ no grand conspiracy, and no administration-wide dishonesty or coverup.”

The Almanac described Mr. Broomfield as a “professional politician” and “generally a solid party loyalist, who tries never to embarrass his party or the administration.”

“He is not a man who seeks the spotlight or looks particularly comfortable in it,” his profile read, “but he performs capably and sometimes with passion.”

Mr. Broomfield was born in Royal Oak, Mich., on April 28, 1922. His father was a dentist.

The younger Broomfield served in the U.S. Army Air Forces during World War II and worked in real estate and property management before winning election to the Michigan House of Representatives in 1948. He served as speaker pro tempore before moving to the Michigan Senate in 1954.

In Congress, Mr. Broomfield was most proud of his vote in favor of the Civil Rights Act of 1964, his family told the Detroit News after his death.

His wife of 62 years, Jane Broomfield, died in 2013. According to the Detroit News, survivors include two daughters, Nancy Broomfield Aiken and Barbara Shaffer; and four grandchildren.