What are 'Green wars' ?

Read the extract given below and answer the questions that follow:

Those who prepare green wars, wars with gas, wars with fire, 

Victory with no survivors, would put on clean clothes

And walk about with their brothers in the shade, doing nothing.

1.  Who are ' those ' in line 1 ?

2.  What are 'green wars'?

3.  Explain :  'victory with no survivors'.

4.  Which figure of speech is used in the above stanza?

1. Over ambitious/eccentric people involved in waging wars to gain dominance.

2. War against environment

3. None may survive to celebrate victory

4. Metaphor – clean clothes / their brothers

green wars, wars with gas, wars with fire'.
The expression refers to the chemical wars which man is waging against man and against nature. Man's activities are polluting the nature and the chemical and nuclear weapons created by him have brought mankind to its dead end.