That's what I was intentionally thinking.
But then I realized it might take only one index case to start another hell on earth like we see in the three current epidemic nations.
So then you e.g. wonder about indirect vectors. Suppose, for example, those guys who pressure washed Duncan's vomit etc. outside his apartment without using any PPE, even had their water bottles too close, were directed to do it quickly, before a few days of heat and UV almost certainly killed the Ebola in it. And then one takes a visit back home.
Or look at this 2nd nurse, who felt compelled to travel to Cleveland to continue organizing her wedding. Suppose that was south of the border instead (essentially no further by air, right?).
Concepts like requiring "a lot" are potentially lethal when the real metric is "it only takes one". Not that Mexico's medical system is non-existent or hopeless by any means, I'd assume it would take another goof for it to get into an area where containment was impractical to impossible.
My general point is that as long as we (the world at large, but the US has a special responsibility to our neighbors) allow unconstrained export of Ebola from its current epidemic nations, bad things are certain to happen. Look at the current Dallas nightmare. Surely, we hope, we'll do better next time. But other nations will also screw up their first cases, and plenty have less margin.
When stakes this high ... well, here's a quick list of the big 3rd World regions and populations, in billions:
Africa: 1.111
Latin America: 0.558
Southeast Asia: 0.618
South Asia: 1.591
Total for above: 3.378
PRC: 1.350
Just how comfortable are we with dicing with the lives of that many people?
While it's hardly inevitable, especially if we can soon develop a safe, easily manufactured and distributed vaccine, what are we going to say to our children if we let 1 billion or more people die because we're now too [fill in the blank] to implement old fashioned quarantines.