The most important region the U.S. knows least about.

On my way to the Wharton Global Forum in Bangkok last week, I thought back to something I was told long ago about Indonesia that actually holds for all of Southeast Asia. It is the most important region of the world we in the U.S. know least about.

I learned so much at our Forum about a region of more than 600 million people whose economy should grow at 6% or more for many years to come. Here are four big takeaways.

1. While many think Asian countries will inevitably have to choose between a past based on U.S. security guarantees and a future dependent on the Chinese economy, Thailand and much of the region show this is a false choice. Instead of “either, or”, they say “both, and” – both continuing deep ties with the U.S., and fostering closer economic relationships with China.

But keeping it this way won’t be easy for the U.S. Take 2 simple facts. On the one hand China has created an infrastructure investment fund for SE Asia with more than $50b in the bank. The region loves it, but the U.S. won’t join. On the other hand the U.S. is pushing a new Asia-Pacific free trade agreement, TPP, that it doesn’t want China to be part of—at least not initially.

2. Economic regionalism in SE Asia is strong but unusual. Strong in that Association of Southeast Asian Nations (ASEAN) is going well, with the goal of creating an internal free market called AEC—ASEAN Economic Community. Unusual in that perhaps the more impressive—and arguably more important—face of ASEAN is in the rest of Asia. ASEAN has foreign trade agreements with the big economies to its north (China, Japan and Korea), west (India) and south (Australia and New Zealand). They want to tie this group together with another acronym, RCEP. You don’t need to know what it stands for. But you do need to know the U.S. isn’t part of it.

3. Building infrastructure is the key to unleashing the full potential of Southeast Asia. The economic upside is high, but the scale of the infrastructure challenge is immense – about $7 trillion according to McKinsey – which is nearly three times total economic output in the region today.

That means the private sector will have to step up, and governments will have to be smart to make this work. It also means private capital from outside the region. Certainly China. Japan is also a big player. But the big upside potential can be for the U.S., not only economically but also politically.

4. I think the growing public role of the private sector will be a major theme in the world of the next decade. But more on that in a later post. For now, let’s just reduce the disconnect between Southeast Asia’s importance and our, at best, partial understanding of the region. The advantages to this knowledge can be lucrative for all.

See our special report: "ASEAN on the Rise" for more in depth coverage of this topic. This report was produced by Knowledge@Wharton, the online business analysis journal of the Wharton School of the University of Pennsylvania.

Geoffrey Garrett is Dean, Reliance Professor of Management and Private Enterprise, and Professor of Management at the Wharton School of the University of Pennsylvania. Follow Geoff on Twitter.