WASHINGTON (NYTIMES) - Richard Lugar, who represented Indiana in the Senate for 36 years and whose mastery of foreign affairs made him one of only a handful of senators in modern history to exercise substantial influence on the nation's international relations, died on Sunday (April 28) in Annandale, Virginia. He was 87.

His death was announced by the Lugar Centre, a Washington think tank he established after leaving office. It said the cause was complications of chronic inflammatory demyelinating polyneuropathy, a nervous system disorder.

Mr Lugar, who had two stints as chairman of the Senate Foreign Relations Committee, had an impact on a wide range of foreign issues, but his most notable accomplishment was indisputably as the co-creator of a programme to help destroy surplus stocks of nuclear weapons around the world.

The project was emblematic of his approach to legislating: It represented an ability to take a long view about complex issues, ran counter to the inclinations of many of his fellow Republicans and was built on a foundation of bipartisan cooperation. It was presented jointly with Senator Sam Nunn, who was chairman of the Armed Services Committee.

The Nunn-Lugar Cooperative Threat Reduction Programme was based on the novel concept of providing United States funds to destroy obsolete nuclear missiles and materials elsewhere in the world.

At the time, the countries of the former Soviet Union said they could not afford the costs of the destruction and were not even providing sufficient resources to properly guard the weapons' storage areas.

The idea was first proposed during the term of President George H. W. Bush, who opposed it, along with many others. It took almost a decade, but Mr Lugar succeeded in persuading Congress, and especially sceptical fellow Republicans, of the need for such a programme.

He was also Congress' leading voice on treaties to ban or limit nuclear weapons, and his judgment on any such proposals was often crucial to whether one could be enacted.

In 1986, President Ronald Reagan chose Mr Lugar to lead an official US delegation to monitor a pivotal election in the Philippines. President Ferdinand Marcos, the country's long-time ruler, appeared to win the vote, turning back a tide of demonstrations in favour of democracy that had forced him to hold the election. The Reagan administration was on the verge of recognising that result.

But Mr Lugar insisted that widespread fraud had occurred and that Mrs Corazon Aquino, the widow of an assassinated opposition politician, should have been declared the winner. He personally exhorted the president about the election irregularities he had witnessed and persuaded him to block any immediate recognition of a Marcos victory. Mrs Aquino was eventually declared the victor.

His independence frequently annoyed many Republicans, both in Washington and Indiana, especially later in 1986, when he helped lead a successful effort in Congress to override Mr Reagan's veto of legislation imposing trade and economic sanctions on the white-led government of South Africa over its policies of apartheid.

Mr Lugar has been frequently compared by historians and congressional scholars to former senators Arthur Vandenberg of Michigan, J. William Fulbright of Arkansas and Henry Jackson of Washington, all of whom had exercised outsize influence in foreign affairs.

But unlike them - and, indeed, unlike most senators - Mr Lugar was known for his extraordinary modesty.

The occasion of roll-call votes typically presents the spectacle of senators lingering on the floor to socialise. In contrast, Mr Lugar would cast his vote quickly after entering and, waving to a senator or two, just as quickly depart.

Mr Lugar was a critic of the 2003 invasion of Iraq. But unlike Mr Fulbright's forceful criticism of the Vietnam War, Mr Lugar's opposition to the Iraq conflict, both the invasion itself and the conduct of the war afterward, was tendered in more moderate terms.

Viewed in light of the current renewed competition with Russia, what Mr Nunn and Mr Lugar managed to accomplish in the Cooperative Threat Reduction Programme was nothing short of remarkable.

The Bulletin of the Atomic Scientist estimated on the 20th anniversary of the programme in 2011 that it had deactivated over 7,500 strategic nuclear warheads, and destroyed more than 1,400 land- and submarine-launched ballistic missiles.

Security was upgraded at nuclear weapons sites, at a time when the greatest fear was that a terror group would take advantage of the chaos in Russia or one of the former Soviet states and buy or steal a weapon.

New jobs were found for the Soviet Union's nuclear scientists and weapons-developers, in an effort to keep them from being tempted to sell their services.

In 2005, Mr Lugar took a young senator, Mr Barack Obama of Illinois, on his first trip as a new member of the foreign relations committee to Russia, Ukraine and Azerbaijan, to examine dismantled weapons and sites. Mr Obama later credited that trip with fuelling a commitment to further reduce the size of the US arsenal after he was elected president three years later.

But while Mr Lugar sometimes compared his efforts to those of George Marshall, the creator of the Marshall Plan that rebuilt Europe, in the last years of his life, the former Indiana senator watched his effort begin to wilt.

Under President Vladimir Putin, the Russians began to resent the US funding of the disarmament effort, and some Russians saw in it a Washington plot to further weaken their own country.

Mr Putin set the country on the course of nuclear modernisation, and Mr Lugar, over a dinner several years ago, lamented that Mr Obama had not been more aggressive in dismantling parts of the US arsenal that he considered no longer necessary.

Mr Lugar was briefly chairman of the Agriculture Committee, but he proved to be an unorthodox farm state senator: He sought to reduce traditional farm subsidies as part of a larger overhaul of federal agriculture policy to allow farmers greater freedom in organising their businesses.

Mr Richard Green Lugar was born in Indianapolis on April 4, 1932, to a farming family with generations of roots in Indiana.

His early life and career were marked by the most traditional signposts of American success. He was an Eagle Scout and president of both his Shortridge High School and Denison University senior classes. He got along so well with his college class' co-president, Charlene Smeltzer, who was known as Char, that they married after graduating. She survives him.

He then became a Rhodes Scholar, and during his studies at Oxford, visited the US Embassy in London in 1957 to enlist in the Navy.

After his return to the United States, Mr Lugar was commissioned a second lieutenant and became a briefer for Admiral Arleigh Burke, the chief of naval operations, who had been a hero of World War II and was renowned as a guileful player in Washington politics. Friends said that this was Mr Lugar's most significant exposure to geopolitical thinking, and probably the single greatest source of his fascination with foreign policy.

After a few years back in Indiana running a machine business, Mr Lugar was elected to the Indianapolis school board. His old high school was by then 90 per cent African American, and he pushed through a plan to make it one of the nation's first integrated magnet schools for the college-bound. Shortridge High soon became evenly divided between black and white students.

But the plan proved highly unpopular politically and was reversed in little more than a year, and in a subsequent campaign for school board president, Mr Lugar was defeated - his first electoral setback.

He rebounded, however. In 1967, at age 35, he was elected mayor of Indianapolis. In his two terms, he helped conceive and enact a plan to unify Indianapolis with surrounding Marion County in all forms of government except for the schools.

With his eyes on higher office, Mr Lugar sought to unseat one of the state's incumbent Democratic senators, Mr Birch Bayh, in 1974. (Mr Bayh died in March.) He lost, but two years later, he succeeded in ousting Indiana's other Democratic incumbent, Mr Vance Hartke.

Re-elected five times, Mr Lugar was always able to campaign as a true son of Indiana, as someone who still operated a large soybean farm there. He had no Democratic opponent in his last successful re-election race, in 2006.

But six years later, he became a target for the unforgiving conservatives of his party's Tea Party wing and was defeated in the Republican primary by Mr Richard Mourdock, the state treasurer. It was apparent that many Republican primary voters had lost patience with Mr Lugar's moderate stances on issues and especially his outspoken faith in the need for cooperation with Democrats.

What was more, attention to foreign relations has traditionally brought few political dividends to senators. And in his case, he held an expansive, internationalist view of world affairs that many party conservatives came to disdain.

The narrative of the Tea Party as an effective spoiler in Republican politics but without wider appeal played out after his primary defeat. Mr Mourdock was defeated in the general election by Democrat Joe Donnelly, in part because of Mr Mourdock's statement that he opposed abortion in cases of rape, saying that any resulting pregnancies were "something that God intended to happen".

Besides his wife, Mr Lugar's survivors include four sons, Mark, Robert, John and David; a sister, Anne (Lugar) Johnson; 13 grandchildren; and 17 great-grandchildren.

After his defeat, Mr Lugar sat down with family and long-time aides to figure out what to do with the rest of his life.

Mr Dan Diller, a Lugar speechwriter for many years, said that Mr Lugar had made it immediately plain that he would not become a lobbyist, the path of many former lawmakers.

Out of those discussions came the idea for the Lugar Centre. In the ensuing years, the centre sponsored studies of the issues he had dealt with for so long as a senator: world hunger, education and nuclear proliferation.

Mr Lugar had been among the most scholarly and courtly of lawmakers, but those characteristics perhaps contributed to his reputation as an unremarkable orator.

In "Richard G Lugar: Statesman of the Senate" (2012), an otherwise highly admiring biography, journalist John Shaw wrote that while Mr Lugar had never been uncomfortable in addressing groups, he was nevertheless "a wooden speaker who is not always adept at gauging his audience and ascertaining the level of detail they are able or willing to absorb".

An exception may have been in 2008, when he accepted an award for ethics in government. He spoke then with passion about his belief in the need for compromise and bipartisanship.

At a time when the Senate was becoming increasingly polarised along party and ideological lines, he argued that senators had a duty to seek consensus across such boundaries - to avoid unnecessary inflammatory rhetoric and accept that those of the other party also love their country.

Bipartisanship, he said, was not simply moderation or willingness to reach compromises but the only sensible way to govern over the long term.

The problem with heavy reliance on opposing the other party, he said, was "whatever is won today through division is usually lost tomorrow".

"The relationships that are destroyed and the ill will that is created make subsequent achievements that much more difficult," he said. Polarisation, he added, "deepens cynicism, sharpens political vendettas and depletes the national reserve of goodwill that is critical to our survival in hard times".