Why did the radical legislative assembly declare war on austria and then prussia in 1792?

Reactionaries and the monarchy wanted war because they thought that the new government would be easily defeated by foreign powers. ... On April 20, 1792, the Legislative Assembly (France's governing body, formed in 1791) declared war on Austria.

when a country suffers, for example, a drought period, the market product is affected for a low offer, in this case, potatoes; the government has to tax to the households, which have to give more money for the potatoes which they consume, that situation make them consume substitute goods even through loans, it could increase the financial market movement and the inflationary phenomena, the business has to increase salaries in order to the employees could buy a more expensive food (potatoes) and in order to inflation tha business had to buy expensive supplies in the factor market, while the rest of the world have to gain more money to consume the same amount of potatoes.