A member of the Senate Foreign Relations Committee urged his fellow lawmakers May 22 to increase their scrutiny of arms exports to minimize the United States’ role in causing civilian casualties.

Sen. Chris Murphy (D-Conn.) said at a Stimson Center conference that few arms sales are debated in Congress even though the United States is the world’s leading weapons exporter and sells many of its lethal wares to developing countries with poor human rights records. In 2016, the United States sold about $40 billion worth of defense equipment to foreign countries, accounting for over a third of the growing international arms trade. 

“The level of oversight today, the level of review, especially from Congress, is simply insufficient,” Murphy said. “We can do better.”

Murphy said he see signs that his colleagues are starting to become more aware of the need for more oversight. In 2016, about a quarter of the Senate voted to block an arms sale to Saudi Arabia, which leads a much-criticized bombing campaign in Yemen’s bloody civil war. A year later, another arms sale to Saudi Arabia came within five votes of being opposed.

“Members are waking up to the very big, potentially cataclysmic downside of unchecked arms sales,” he said.

The continued “humanitarian nightmare” in Yemen could lead to another Senate vote on an upcoming sale of precision-guided weapons, he added. While Saudi Arabia insists its coalition in Yemen is getting better at avoiding civilians, Murphy believes there is “little meat on the bone” to support that assertion.

Murphy does not expect increased scrutiny to come from the Trump administration, which announced policy changes in April aimed at streamlining and expediting the arms export process. He worries that the administration will allow already robust arms sales to Persian Gulf nations to increase “at a time when, frankly, the Middle East absolutely does not need any more weapons.”

Despite his concerns, Murphy, whose state is home to several major defense contractors, emphasized that he supports many arms sales, especially those to “allies that are going to use them well.”

He declined to say whether he will support or oppose the sale of Lockheed Martin [LMT]-built F-35 Lightning IIs to Turkey, calling the U.S.-Turkish relationship “complicated.” While Turkey has been criticized for committing human rights abuses and intervening in Syria’s civil war, it remains a NATO ally, he noted.