The correct answer is B) one country attacks another because of the promise in made to a third country.
<em>The event that is an example of the Allied system is one country attacks another because of the promise in made to a third country.</em>
In the Allied system, countries sign treaties or agreements about cooperation in trade and military. So when a country needs help, the other country or other countries come to help it. For instance, that was the case of World War II. The allies were Russia, Great Britain, France, and the United States. The Axis Powers were Germany, Italy, and Japan.
The other options of the question were a) one country engages in a military race with another country, c) one country conquers many other countries to exploit its resources, and d) one country loses control of many of its overseas countries.
