Efforts to control the $70 billion a year global market in conventional weapons got a big boost when the United States signed the United Nations arms trade treaty, joining more than 100 other countries in affirming the need to keep these weapons out of the hands of unscrupulous regimes, militants and criminals.

But the work is far from done. At least 50 member countries, including the United States, must still carry out the next step and ratify the treaty for it to take effect; only six have done so. Proponents fear final ratification could take years, and it would be a travesty if it does.

The treaty, which took seven years to negotiate, is a pioneering agreement that is unquestionably needed. It covers global trade in tanks, armored combat vehicles, large caliber weapons, combat aircraft, attack helicopters, warships, missiles and launchers, small arms and light weapons — the kinds of weapons that are fueling conflicts and killing innocents in Syria, Sudan, the Democratic Republic of Congo and beyond.

The treaty would require states to review all crossborder arms contracts, establish national control systems and deny exports to purchasers who might use the weapons for terrorism or violations of humanitarian law, including genocide. In April, the 193-member General Assembly adopted it overwhelmingly by a vote of 154 to 3, clearing the way for individual states to sign and then ratify the pact. The states in opposition were familiar outliers in the international system: North Korea, Syria and Iran.