Obama-era sales to Saudi Arabia were in keeping with sales to other Gulf states: Both Qatar and the United Arab Emirates bought a tremendous amount of U.S. arms between 2009 and 2017. Qatar bought more U.S. arms than any other state in 2014 and, in the waning days of the Obama administration, announced that it would buy nearly $4 billion in Boeing-made F-15s in addition to $19 billion in commercial aircraft, also from Boeing.

Overall, the Arab Gulf states went on a spending spree during the Obama years, and most of the money was spent on American arms.

So why didn’t you hear a lot about this from Democratic politicians during the 2016 election season? There are two main reasons—one strategic and one moral.

Strategically, not everyone is convinced that arming the Arab Gulf states to the teeth is a wise idea. Some worry that these arms might someday endanger Israel’s security, while others worry the Arab Gulf states might be encouraged to use their new toys on disastrous military interventions against Iran or Iranian proxies in, say, Yemen.

The quick and unsatisfying answer to these concerns is the global market. The Arab Gulf states have money, and that money will buy the weapons that are available. If U.S. arms are not for sale, fine: French, Chinese, or Russian arms will be. (And if you don’t believe me, look at the way in which Gulf states—frustrated by U.S. export controls on drone technology—are turning to the Chinese.) Selling U.S. arms to the Gulf states, by contrast, further ties them to U.S. interests by deepening cooperation and interoperability between the U.S. military and its Gulf partners. One of the reasons Qatar wanted to buy U.S. fighters to partially replace its French-made fleet, for example, was because they discovered how difficult it was for their existing fighter aircraft to fly with the U.S. air force as part of coalitions over Libya and Syria.

Arms sales also drive down the cost of our own weapons and thus the amount of money U.S. tax-payers have to spend on defense instead of other priorities like, say, the State Department, school lunches, or housing subsidies. Here’s one example: Because the United States is buying fewer F-35s than originally planned and using more of its “fourth generation” fighters (F-15s, F-16s, etc.) in the skies over Iraq and Syria than previously anticipated, the Department of Defense will likely need to buy more of those fourth generation fighters in the coming years. The recent sales of F-15s to Qatar, F-18s to Kuwait, and F-16s to Bahrain will drive down the cost per plane for the Pentagon. That’s a good thing—at least financially.

Morally, though, many progressives just grow ill at the idea of selling weapons abroad. Senator Chris Murphy, for example—one of the more eloquent and consistent critics of U.S. arms sales in the Senate, even though his own state has a very robust defense industrial base—sees nothing admirable about the idea of selling weapons to the Saudis that might be used in Yemen. Other progressives agree: Yes, they argue, we understand the demand of the market will be met by someone, but do we have to be complicit in providing the supply? In other countries, progressives have even taken to the courts in an effort to halt sales.