Twenty years after its establishment, the World Trade Organization finally reached its first global trade deal last night at the meeting of the world’s trade ministers in Bali. The successful agreement foiled expectations that this meeting, like all others of the Doha Round, would end in failure and acrimony. Media outlets have been reporting the Peterson Institute’s estimate of $1 trillion in higher global output as a result of the deal, but what’s most interesting about the deal is that it happened only because the member states decided to focus on a narrow slice of the issues under discussion in the Doha Round. The deal focuses mostly on streamlining customs procedures to facilitate timely cross-border transportation, along with measures to eliminate tariff and quota barriers against exports from “least developed countries” to richer countries, to reduce agricultural export subsidies (here the deal merely makes a “strong political statement” and doesn’t require specific changes in law), and to permit developing countries’ governments to stockpile food.

Why did it happen? Ten days ago, after talks in Geneva, WTO head Roberto Azevedo warned that global trade talks would collapse if ministers did not narrow down the scope of their deliberations to issues on which consensus was achievable. Global trade talks have been bogged down over the last 20 years over severe distributional issues: developing-country governments want sharp cuts in rich-world agricultural subsidies, tariffs, and quotas, while rich-country governments want their poorer counterparts to cut trade barriers on services, beef up intellectual-property enforcement, and liberalize foreign investment. None of those big issues were solved in Geneva and Bali. A narrow deal on customs procedures happened because the distributional and enforcement issues here are far less severe. Few governments have any interest in holding up traffic at the border longer than necessary. Simplifying customs procedures is more like a coordination game than a Prisoner’s Dilemma: everyone benefits if forms are standardized and simplified. Rich-country governments also promised poor-country governments help with hiring customs officials to help speed up processes.

The conventional wisdom in international relations is that a broad scope of issues helps international organizations solve distributional problems, all else equal, because broad scope makes it easier for governments to trade off gains to one side on one dimension with gains to the other on another dimension. But all else was not equal here: some issues faced much lower distributional conflict than others, and on those it was relatively easy for governments to reach agreement. They chose to go for a small deal rather than a big one because, frankly, the WTO needed a win. Another collapse of talks would have called into question whether multilateral trade liberalization is even possible.

This deal does not end the Doha Round. Talks will continue on the “big issues” mentioned above. This is fortunate, since the Bali deal does little to reduce the extent to which U.S. and European agricultural policies kill poor people. While the deal helps with market access for least developed countries, essentially all rich countries have already implemented duty-free, quota-free access for these countries’ exports, and least developed countries contain merely 12% of the world’s population and less than half of those living in extreme poverty. There need to be binding legal limits, actionable before the Dispute Settlement Body, on agricultural subsidies, quotas, and tariffs in rich countries.