The correct answer to this open question is the following.
Although you did not attach the speech or a link to it, we can say the following.
President Wilson's intention in beginning his "Declaration of Neutrality" by saying "The effect of the war upon the United States will depend upon what American citizens say and do" was to make a clear statement that he would pay heed to the opinion of the American citizens regarding the US Participation in foreign affairs, in this case, the actions in Europe during World War I.
That is why President Wilson clearly stated that <em>"Every man who really loves America will act and speak in the true spirit of neutrality, which is the spirit of impartiality and fairness, and friendliness to all concerned." </em>
The speech affected US involvement in World War I in that it caused the US to remain isolated and neutral.
Although President Woodrow Wilson wanted to maintain a foreign policy of neutrality, critical events such as the inking of the Lusitania ship and the interception of the Zimerman telegraph where Germany asked the help of México supporting German troops, made Wilson enter the war. The United States entered World War 1 on April 6, 1917, to support Great Britain and France.
