Germany worried about the alliance between France and Russia, for if they declared war on either one of them, they would have to fight a war in 2 fronts, and usually, when fighting a war in 2 fronts, your troops and supplies are strained, and you cannot use your full force on either side
hope this helps
A lack of central governments with wealth and power
Vietnam. during 1975 the north Vietnamese wanted Vietnam to become a communist country and the south wanted to remain a diplomatic state. the american government sent soldiers to back their Vietnam allies in what was one of many "proxy" wars fought between the USSR and america. the north implemented extreme guerrilla tactics and overall the Americans had to pull out of the country due to a loss of support and funding. this marks one of the very few losses for the american army in history.
