the modern world is so interlinked via financial globalisation. The economies of the world, whilst they have their own rhythm to some extent, after often treated as pawns by the veracity of the global markets.
Some Countries are undoubtedly victims of their own political issues - see Erdogan in Turkey or Putin in Russia, even the South Africans have been busily running their own economy to achieve domestic political ends. (And in Developed markets, the UK too...)
However, just as many are buffeted by the markets. Egypt and India stand out here. Egypt because as a geography and demographic entity it is a nightmare. An arab country with no oil, but also not enough food or water for its fast growing population. Indeed, Egypt must for these reasons alone be one of the most unstable countries in the world as it matters little what its politicians do faced with such a dismal situation.
In India, they have had a strong, reforming government for a number of years and indeed, though no China, things have been going well for India. However, India also has no oil, so the companies there which import are suffering from huge increases in import costs and the rupee has fallen to all time lows against the dollar. Of course, India exports a lot and receives plenty of foreign currency so its stock market and its bit exporting businesses are doing very well - but the economy as a whole still ends up on a knife-edge. Adding to its complex situation, the US is demanding India comply with new oil sanctions on Iran - but India imports a million barrels a day of crude from Iran at huge discounts to market and this helps it to limit the level of oil price inflation entering its economy.
Finally, we have not even mentioned Argentina, itself in another IMF rescue but with a huge government deficit, weak currency and 30% inflation - so trapped is Argentina by its poor performance that even many economists have given up trying to find a way out for the Country.
Collectively, these countries account for a big share of Global GDP - yet all are in crisis somehow even whilst Trump engineers a boom in the US and the EU slowly recovers from the financial crisis and Global growth is strong. Emerging Markets are always at risk of currency flight back to the West and this seems to be happening again with China trying in a limited way only to interfere when it spots resources to be bought on the cheap (hence of these countries, only Russia really appeals).
Will the crisis spill over - it does not seem so at the moment as the causes of the distress are a benefit to the main markets, but politically there are big risks especially in Turkey and Egypt - as well as Russia of course but there at least the Government is safe and there is no foreign debt to worry about.