Stiglitz wrote  in 2003:
War is widely thought to be linked to economic good times. The second world war is often said to have brought the world out of depression, and war has since enhanced its reputation as a spur to economic growth. Some even suggest that capitalism needs wars, that without them, recession would always lurk on the horizon.
Today, we know that this is nonsense. The 1990s boom showed that peace is economically far better than war. The Gulf war of 1991 demonstrated that wars can actually be bad for an economy.
Stiglitz has also said that this decade’s Iraq war has been very bad for the economy. See this , this  and this .
Former Federal Reserve chairman Alan Greenspan also said in that war is bad for the economy.
In 1991, Greenspan said that a prolonged conflict in the Middle East would hurt the economy .
And he made this point again  in 1999: