Roosevelt's policy of watching over affairs in the We
Hemisphere was known as the

The Roosevelt Corollary to the Monroe Doctrine.

Explanation:

The Monroe Doctrine is a 1823 idea turned into a U.S. foreign policy guideline that states that  any intervention of European powers in the affairs of the Western Hemisphere´s nations will be taken as a hostile act against the security of the United States. Washington wanted European countries to abstain from such interference and declared it will not intervene in the affairs of Europe.

President Theodore Roosevelt followed a policy of active diplomatic and military intervention in Latin America and the Caribbean. The policy means that the U.S. should intervene in regional countries facing instability and that are highly indebted to make sure they meet their international financial obligations toward European creditors. The aim was to avoid any European intervention in a regional country, and it was attuned to the Monroe Doctrine. That´s why it was called the Roosevelt Corollary, and it led to US military interventions in some countries.

Fall of soviet union leads to Germany to be united again.

Explanation:

Thousands of jubilant Germans brought down the Berlin Wall in November 9, 1989 which is the most visible symbol of division located at the heart of Europe. In 1990, the former communist leaders loss their power, and Germany was united again. The government changed from communism to a democracy, from planned market to open markets, from government control to private citizen, and from the Soviet Union to the European Union are the longlasting consequences of the fall of the soviet union.