There are no atheists in foxholes; is there any differentiation in an emerging market meltdown? Emerging market policymakers have had their strenuous efforts to reduce vulnerability stress-tested to the extreme by the market panic this week.

There have been myriad attempts to sort EMs into different categories susceptible to different shocks, the most recent being the Morgan Stanley typology reproduced here. But the history of previous episodes of market turmoil, most particularly the taper tantrums of last year and early this year, is that all EMs can get drawn into the maelstrom.

It is obviously way too soon to draw firm conclusions about how much EM assets will all suffer together from the latest asset price turmoil — not least because the People’s Bank of China stepping in with a rate cut on Tuesday helped to reverse some of the falls. But the history of previous episodes of emerging market turmoil, plus some tentative signs in recent months and days, suggest that EMs that have done their policy groundwork may be rewarded.