The historians might even conclude that, of the two, Caligula made the wiser choice.
A horse, for example, could probably be trusted not to stand in the way of an international treaty designed to banish nerve gas and other weapons of chemical warfare from the planet. The same may not be said of the 75-year-old Republican from North Carolina who has decided single- handedly to block America's ratification of the Chemical Weapons Convention, an agreement endorsed by 68 countries to ban the use, production and accumulation of such weapons.
Last week Senator Helms came under intense pressure from all quarters to change his mind. A special White House team, anxiously aware that barely 10 weeks remain for the convention to come into effect, held urgent talks with Republican leaders. George Bush joined Madeleine Albright, the secretary of state, at a platform in Houston to urge American ratification of the treaty. The editorial pages of the leading US newspapers were packed with articles fiercely protesting Senator Helms' hard-line isolationist stance.
Why is Senator Helms determined to distance America from the humane nations of the world and associate the superpower democracy with states, like Iraq, Libya and North Korea, that see no value in outlawing chemical weapons? Partly because of a fundamentalist habit of mind - Christian, not Muslim, extremism - that places less value on human life than on the life hereafter; but specifically because, he says, he first wishes to see the United Nations, Sodom and Gomorrah, reformed to his absolute satisfaction.
Other conditions he has imposed before he will agree to ratify the chemical weapons convention are commitments from the White House to restructure the State Department - a body he considers superfluous to American needs; abolish the Arms Control and Disarmament Agency and the US Agency for International Development, which dispenses charity to the Third World or, as he puts it, pours money down "a rathole"; and revive the defunct anti-ballistic missile programme, that product of Ronald Reagan's B-movie imagination popularly known as the Star Wars system.
As Alton Frye of the Council of Foreign Relations in Washington delicately put it, "he's applied linkage in extremis here, basically pricing the Chemical Weapons Convention out of the market". A less polite way of saying the same thing is that he is holding a treaty of immense value to the human species hostage to his own ludicrously unrealistic pet projects.
Senator Helms is not new to this game. Pressing the very same points, he held up the Senate nominations of 30 US ambassadors for several months in 1995, thus curtailing the operations of 15 per cent of America's foreign embassies.
This is the same Senator Helms who invented the Helms-Burton Bill, now passed into law, which denies entry into the US to foreigners who do business with Cuba. Outrage has been the reaction in Canada and Europe, to which the senator's reply has been to compare Fidel Castro's "appeasers" to Neville Chamberlain and to remark, "Where I come from, when you do business with a tyrant you're dealing in blood money."
Which begs the question, why was Senator Helms so happy to do business with South Africa during the apartheid era? Fiercely opposed to international sanctions of any kind, he played the role of witting or unwitting stooge to the two most sinister projects devised by the South African intelligence apparatus by lending his support to Mozambique's unspeakably savage Renamo guerrillas and to the undeclared terrorists of Mangosuthu Buthelezi's Inkatha movement. Publicly he praised Renamo and Inkatha, privately he sought to raise funds for them.
But Latin America was always his biggest obsession. He would support any tyrant, no matter how evil, so long as he was opposed to communism. His best friend in El Salvador was Roberto D'Aubuisson, the neo-fascist death squad leader identified by the State Department as the man behind the tiny Central American country's crime of the century, the assassination of Archbishop Oscar Romero while he was saying mass. Confronted one day with the evidence of D'Aubuisson's death squad connections, Senator Helms said: "All I know is that D'Aubuisson is a free enterprise man and deeply religious."
Among his other friends in the hemisphere he counted General Augusto Pinochet of Chile; Raul Cedras, the Haitian dictator who sought violently to stop the rise to power of the democratically elected Jean-Bertrand Aristide; and successive Guatemalan military regimes, consistently the most barbaric in Latin America during the 1980s.
He also formed a deep attachment to the Argentine generals who seized power in a coup in 1976, precipitating a six-year reign of terror during which 20,000 people "disappeared" and which only ended with Britain's victory in the Falklands War. Senator Helms was the only member of the US Senate who took Argentina's side in that war, his argument having been that "the tilt toward Britain will destroy the coalition we must have if we are to prevent a communist take-over of Central America".
On domestic policy he takes his lessons from a rigorous Baptist reading of the Old Testament, not the New. There was a time when he appeared to take the Biblical view once shared by his white South African friends that black people had been afflicted with the curse of Ham. He described the Civil Rights Act of 1964, a law which finally put to rest America's shameful history of legislated racial discrimination, as "the single most dangerous piece of legislation ever introduced in the Congress". He has, by various accounts, moderated his public statements on race since, but he still holds to the view that Martin Luther King was "a man of tasteless immorality".
Where he has made no concessions to evolving popular wisdom is on the subject of homosexuality. "The Bible is unmistakably instructive about the sin of sodomy," he declared two years ago. "I confess I regard it as an abomination." An ardent opponent of government funding for Aids research and education, he said last year that HIV was acquired through "deliberate, disgusting, revolting conduct ... we've got to have some common sense about a disease transmitted by people deliberately engaging in unnatural acts".
A "wages of sin is death" man, the senator has no patience either for those weak souls unable to suppress their baser heterosexual urges. As vigorous an enemy of condoms as of abortion, aid to single teenage mothers and erotic art, he once chastised a university lecturer in North Carolina for including Andrew Marvell's To His Coy Mistress in his English course, whereupon the lecturer was removed.
All of which leads to an overwhelming question, what possessed the Republican Party to elect such a dinosaur chairman of the mightily powerful Senate Foreign Relations Committee in the first place?
The die was cast in 1987, when he defeated Richard Lugar, the man with the most sophisticated grasp of foreign affairs on Capitol Hill, for the post of leading Republican on what was then a Democrat-controlled foreign relations committee. His Republican colleagues chose Senator Helms for one reason and one reason alone, the party's unshakeable commitment to the principle of seniority. It was the same suicidally sentimental imperative that drove the Republican Party last year to choose the veteran Bob Dole as its presidential candidate. Senator Lugar had served fewer years in the Senate and, never mind his manifestly superior aptitude for the job, did not have a chance. Senator Helms emerged from that vote to proclaim "a victory for the seniority system".
It was a victory, as it has turned out, for a vision of humanity that embraces chemical and nuclear weapons proliferation, deeply religious free-market murderers, homophobes, bigots and misery without end for the world's poor. It's not the horse, but Caligula that has ascended the Senate throne.
The convention everyone wanted - until now
The Chemical Weapons Convention has been endorsed so far by 68 countries, including Britain but excluding the United States, where ratification awaits a decision by the Senate.
The deadline is 29 April, after which countries which have not ratified their commitment to the convention will be denied the right to participate in an international commission appointed to verify adherence to the convention's terms and carry out inspections of suspected violators.
Countries which fail to sign up to the convention will also be subject to punitive trade measures affecting manufacturers of benign chemicals.
The US government has been an enthusiastic proponent of such a convention since global negotiations to reduce the risks of chemical warfare began during the presidency of Ronald Reagan, continuing through the presidency of George Bush. President Clinton said in his State of the Union address earlier this month that the US had "no more important obligation" than to ratify the convention. The Pentagon, the US intelligence community and US chemical manufacturers are all in favour too.
Should the Senate miss the April deadline, in accordance with the wishes of Senator Helms, the US will not only suffer grave political embarassment, it will be denied entry to the convention's powerful ruling body and the US chemical industry will endure losses calculated at $600m (pounds 375m) in lost export opportunities.