The U.S. government helps by providing financial and humanitarian aid. This money is to help the government and the people from wars, natural disasters, etc. Sometimes they exchange their help for a promise to help America's democracy. American's also help by supporting charities and non-profit organizations. American's do so many things to help the Middle Eastern gain independence for very little in return.
This poster encourages support for US entry into World War I to protect the values of liberty in America. It suggests that Germany is made with power and will not stop with Europe but will continue to the US to destroy America as well.