Case in point, at least three major emerging market nations announced they are bracing for currency war. 

First India, where NDTV ask rhetorically "How China's Devaluation of Renminbi Impacts India" and answers:

1) The Indian rupee slipped to a two-month low of 64.26 against the US dollar on Tuesday tracking the devaluation of the renminbi. Other currencies such as the Australian dollar and the South Korean won also lost ground.

2) The over 0.5 per cent fall in the rupee weighed on traders' sentiments, resulting in a drop in equity markets. Both the BSE Sensex and the Nifty traded with 0.4 per cent losses.

3) According to SV Prasad of Chime Consulting, renminbi's devaluation may push the Reserve Bank of India to cut interest rates in India. Lower interest rates will put off foreign investors and will further weaken the rupee, he added.