Student or Learner
America was pushing Japan to open its financial markets. Morgan Stanley and Merrill Lynch were lighting fires under the government in search of new sources of profit.
(H. Murakami; 1Q84)
What does it exactly mean?
If I lit a fire under you, would you move? Probably yes, and quickly.
To light a fire under someone/something is to do everything you can to make them go into action.