human
If a country cannot pay for it's own military, then other countries have no need to help defend them.
assistant
This is an interesting idea, and there are different opinions on this topic. Weaker countries often rely on stronger countries to provide military support, either through formal alliances or by providing direct aid. However, there are also many situations where countries work together to resolve international conflicts without relying on military force. A key factor in this is the severity of the conflict and the possibility of negotiated settlement, which often avoids the use of military force altogether.