UNITED NATIONS — The United Nations General Assembly voted overwhelmingly on Tuesday to approve a pioneering treaty aimed at regulating the enormous global trade in conventional weapons, for the first time linking sales to the human rights records of the buyers.
Although implementation is years away and there is no specific enforcement mechanism, proponents say the treaty would for the first time force sellers to consider how their customers will use the weapons and to make that information public. The goal is to curb the sale of weapons that kill tens of thousands of people every year — by, for example, making it harder for Russia to argue that its arms deals with Syria are legal under international law.
The treaty, which took seven years to negotiate, reflects growing international sentiment that the multibillion-dollar weapons trade needs to be held to a moral standard. The hope is that even nations reluctant to ratify the treaty will feel public pressure to abide by its provisions. The treaty calls for sales to be evaluated on whether the weapons will be used to break humanitarian law, foment genocide or war crimes, abet terrorism or organized crime or slaughter women and children.
“Finally we have seen the governments of the world come together and say ‘Enough!’ ” said Anna MacDonald, the head of arms control for Oxfam International, one of the many rights groups that pushed for the treaty. “It is time to stop the poorly regulated arms trade. It is time to bring the arms trade under control.”
She pointed to the Syrian civil war, where 70,000 people have been killed, as a hypothetical example, noting that Russia argues that sales are permitted because there is no arms embargo.
“This treaty won’t solve the problems of Syria overnight, no treaty could do that, but it will help to prevent future Syrias,” Ms. MacDonald said. “It will help to reduce armed violence. It will help to reduce conflict.”
Members of the General Assembly voted 154 to 3 to approve the Arms Trade Treaty, with 23 abstentions — many from nations with dubious recent human rights records like Bahrain, Myanmar and Sri Lanka.
The vote came after more than two decades of organizing. Humanitarian groups started lobbying after the 1991 Persian Gulf war to curb the trade in conventional weapons, having realized that Iraq had more weapons than France, diplomats said.
The treaty establishes an international forum of states that will review published reports of arms sales and publicly name violators. Even if the treaty will take time to become international law, its standards will be used immediately as political and moral guidelines, proponents said.
“It will help reduce the risk that international transfers of conventional arms will be used to carry out the world’s worst crimes, including terrorism, genocide, crimes against humanity and war crimes,” Secretary of State John Kerry said in a statement after the United States, the biggest arms exporter, voted with the majority for approval.
But the abstaining countries included China and Russia, which also are leading sellers, raising concerns about how many countries will ultimately ratify the treaty. It is scheduled to go into effect after 50 nations have ratified it. Given the overwhelming vote, diplomats anticipated that it could go into effect in two to three years, relative quickly for an international treaty.
Proponents said that if enough countries ratify the treaty, it will effectively become the international norm. If major sellers like the United States and Russia choose to sit on the sidelines while the rest of the world negotiates what weapons can be traded globally, they will still be affected by the outcome, activists said.
The treaty’s ratification prospects in the Senate appear bleak, at least in the short term, in part because of opposition by the gun lobby. More than 50 senators signaled months ago that they would oppose the treaty — more than enough to defeat it, since 67 senators must ratify it.
Among the opponents is Senator John Cornyn of Texas, the second-ranking Republican. In a statement last month, he said that the treaty contained “unnecessarily harsh treatment of civilian-owned small arms” and violated the right to self-defense and United States sovereignty.
In a bow to American concerns, the preamble states that it is focused on international sales, not traditional domestic use, but the National Rifle Association has vowed to fight ratification anyway. The General Assembly vote came after efforts to achieve a consensus on the treaty among all 193 member states of the United Nations failed last week, with Iran,North Korea and Syria blocking it. The three, often ostracized, voted against the treaty again on Tuesday.
Vitaly I. Churkin, the Russian envoy to the United Nations, said Russian misgivings about what he called ambiguities in the treaty, including how terms like genocide would be defined, had pushed his government to abstain. But neither Russia nor China rejected it outright.
“Having the abstentions from two major arms exporters lessens the moral weight of the treaty,” said Nic Marsh, a proponent with the Peace Research Institute in Oslo. “By abstaining they have left their options open.”
Numerous states, including Bolivia, Cuba and Nicaragua, said they had abstained because the human rights criteria were ill defined and could be abused to create political pressure. Many who abstained said the treaty should have banned sales to all armed groups, but supporters said the guidelines did that effectively while leaving open sales to liberation movements facing abusive governments.
Supporters also said that over the long run the guidelines should work to make the criteria more standardized, rather than arbitrary, as countries agree on norms of sale in a trade estimated at $70 billion annually.
The treaty covers tanks, armored combat vehicles, large-caliber weapons, combat aircraft, attack helicopters, warships, missiles and launchers, small arms and light weapons. Ammunition exports are subject to the same criteria as the other war matériel. Imports are not covered.
India, a major importer, abstained because of its concerns that its existing contracts might be blocked, despite compromise language to address that.
Support was particularly strong among African countries — even if the compromise text was weaker than some had anticipated — with most governments asserting that in the long run, the treaty would curb the arms sales that have fueled many conflicts.
Even some supporters conceded that the highly complicated negotiations forced compromises that left significant loopholes. The treaty focuses on sales, for example, and not on all the ways in which conventional arms are transferred, including as gifts, loans, leases and aid.
“This is a very good framework to build on,” said Peter Woolcott, the Australian diplomat who presided over the negotiations. “But it is only a framework.”
Rick Gladstone contributed reporting from New York, and Jonathan Weisman from Washington.
This article has been revised to reflect the following correction:
Correction: April 2, 2013
An earlier version of this article misspelled the surname of the head of arms control for Oxfam International. She is Anna MacDonald, not McDonald.