Sure enough, not to Eder's expectations, on the tenth day after the outbreak of the Russian Revolution, the United States announced the severance of diplomatic relations with Germany. The reason was that Germany's unrestricted submarine warfare threatened the freedom of shipping and trade in the United States.

When the founding president of the United States, George Washington, left office in 1796, he confessed to the public: "The great principle of our dealings with foreign nations is that we should have as few political ties as possible in the extension of our commercial relations with them...... It would certainly be unwise to involve ourselves in Europe's regular political rise and fall or frequent foe-foe rivalry with some artificial connection. John Adams put it bluntly: "We should make it our first principle and never forget: neutrality in all future wars in Europe." "The tone of diplomacy set by America's founding leaders is known as isolationism.

Thus, after the outbreak of World War I in 1914, then-US President Wilson declared the United States neutral and demanded that the United States "must remain neutral not only in name but also in fact." In his telegram to the envoys of the belligerent countries, he also earnestly exhorted: "Do not show any non-neutral feelings, not in words. ”

Since the independence of the United States, it has actually been surrounded by the colonies of Britain, France, and Spain, which are the great powers of Europe, and it is a wise choice to keep a distance from all European powers. There is another important reason for maintaining neutrality, that is, the United States is relatively weak in national strength, and it needs to maintain its obscurity, seek a peaceful environment for development, and wholeheartedly seek development to enhance its own strength.

On the eve of the Spanish-American War in 1898, the American army was less than 30,000 men, and it was inferior to Bulgaria in the world. Considering the size of the U.S. landmass, this number is pitifully small, and the naval power is even more insignificant. In addition, the United States is a country of immigrants, and European immigrants occupy an important position, and excessive involvement in the European war may also lead to the division of different European ethnic groups in the country because of their allegiance to their country of origin. By remaining neutral and watching the fight, you can profit from the strife in Europe.

War will create a lot of logistical needs, which are opportunities for American companies, so the United States not only neutralizes itself, but even hopes that other countries will "let the bullets fly". Throughout the 19th century, the United States took advantage of the contradictions between European countries to expand its territory from east to west, desperately expanding its strength.

The United States purchased Louisiana from France in 1803, forced Spain to give up Florida in 1819, annexed northern Mexico to become Texas in 1845, acquired Oregon by treaty with Great Britain in 1846, annexed territories from Mexico to form New Mexico and Alta California in 1848, and Alaska from Tsarist Russia in 1867.

The late 19th and early 20th centuries were the "Gilded Age" of the United States, and society was making rapid progress on the road to progress. The hard power indicator is that in 1890 the United States was already the world's largest steel production, and by 1900 the United States produced 13.3 million tons of steel, about the size of Britain and Germany combined. The relative share of the United States in world industrial production surpassed that of Great Britain in 1900 at 23.6 percent, compared to 18.5 percent for Great Britain. The relative total industrial potential also exceeded that of Great Britain by a quarter in 1900.

The population of the United States was only three million in 1783 and 32 million in 1860, and from the eighties of the 19th century, the population of the United States increased rapidly, mainly a large number of immigrants from southeastern Europe began to pour into the United States. From 39 million in 1870 to 63 million in 1890.

From 1898 onwards, the U.S. military grew rapidly to 100,000 men, of whom 10,000 were stationed in Cuba and 60,000 were fighting in the Philippines. In 1884, the U.S. Navy also ranked 12th in the world.

In 1914, the United States had a population of 98 million, a national income of $13.7 billion, more than 13 times that of the United Kingdom's $1 billion, and a per capita income of $377, which was much higher than Britain's $244. The combined national income of all European countries, including Russia, is on par with that of the United States. The U.S. Navy is the third largest in the world, after Britain and Germany. At this time, even the most ignorant people in the Old World can feel the strength of the American muscles and try to adapt, and of course this includes the United States itself.

It is not objective to conclude that the United States will inevitably abandon isolationism just because it is muscular. A major shift in foreign policy inevitably involves a challenge to core interests. A closer look at America's isolationism is not just about neutrality.

It "refers specifically to the relationship between the United States and Europe, not to the rest of the world, and specifically to politics and military, not to economic and cultural." The first meaning is that the United States is not involved in military and political disputes in Europe, and other places outside Europe are not necessarily neutral, especially the Americas.

In his State of the Union address to Congress in 1823, U.S. President James Monroe made the red line of isolationism clear: "We regard all attempts by European nations to extend their institutions to any part of the Western Hemisphere as a danger to our peace and security." We have not and will not interfere with the existing colonies or possessions of any European country, but any interference by any European country in order to oppress those countries that have declared their independence will be regarded as an unfriendly sign to the United States. ”

In other words, the United States does not care if the great powers make trouble in Europe, but it is the core interest of the United States to make trouble in the Americas. The second level is that isolationism is only military and political non-involvement, but economically and culturally it requires equal opportunities. Even in your colonies, open doors and interests should be equalized, and freedom of navigation at sea on the high seas should be demanded by a strong country, and this principle has the same confidence as the Monroe Doctrine, which is to say that American isolationism has conditions and a bottom line. In short, isolationism is in the service of the economy, and profit is king.

After the outbreak of World War I, the belligerents filled the pockets of American businessmen with massive, high-priced military orders. In August 1914, France shipped large quantities of gold to the safe of the Morgan Company in the United States in exchange for a loan of $100 million. In October 1915, Morgan lent another $500 million to Britain and France, which could only be used to buy American goods. There are also more than 470 million loans and military supplies to Russia. During World War I, the United States also refused to trade with Germany and other Allied powers.

But Britain's maritime power was too strong to block trade with Germany. The British army's maritime superiority quickly turned America's neutral trade into a de facto blood transfusion channel to the Allies, and the Anglo-American maritime trade became the hatred of the Germans, and the contradictions between the United States and Germany began to intensify.

On February 4, 1915, the German Admiralty began unrestricted submarine warfare, creating a blockade zone on the British islands, and all surface vessels, both military and civilian, were to be attacked without warning. Freedom of shipping is restricted, and Americans can't do business.

On March 28, 1915, the American cruise ship "Faraba" was sunk and an American died. Five weeks later, a large British passenger liner, the Lusitania, sank off the coast of southern Ireland, killing more than 1,000 people, 128 of whom were Americans. The Lusitania incident caused civilian casualties and caused an uproar in American society. While the Germans exclaimed, "We look with joyful pride at this recent exploit of our Navy," public opinion was formed among the American public that the Germans were heinous and did not respect basic human rights.

President Wilson sent a diplomatic note in response to this question, which was extremely strongly worded and threatening. Dissatisfied with the note, which could lead to a war in diplomacy, Brian, the pacifist who was the US Secretary of State at the time, resigned in anger. In fact, Wilson's biggest political goal at the time was to be re-elected in 1916, and during his campaign campaign he used the slogan "He kept us away from war" to make it possible for the United States to continue trade without going to war.

Wilson, who came from the South, desperately needed the votes in the Northeast and the Great Lakes region, which benefited most from the war trade, so that these voters could continue to profit from the war. Not paying for the war was a prerequisite for Wilson's re-election. Fortunately, after this, the submarine warfare in Germany subsided somewhat, but on March 24, 1916, the "Sassex" incident occurred again. A German submarine sank the French passenger liner "Sarssex" in the English Channel without warning, seriously injuring or drowning 80 passengers, including 4 Americans. Although this incident is not serious, it is tantamount to adding fuel to the fire of the already deteriorating relationship between virtue and Germany.

In 1916, the U.S. trade surplus "increased from more than $430 million to more than $2 billion, that is, an increase of 3.7 times." The war finances of World War I enabled the United States to accelerate the upgrading of its industrial structure, and its industry and agriculture, especially its military industry, developed extremely rapidly, and it also won the initiative financially, changing from a debtor country to a creditor country. Comparing the volume of U.S. transactions with the Entente and the Allies, we can see that the U.S. and the Entente countries were more economically bound, and the U.S. exported capital to Germany accounted for only 2% of the total U.S. capital exports. And if the Entente were defeated, the huge investment of the United States would come to naught, which is obviously not what the Americans want to see.

The Germans were at a disadvantage in economic warfare and propaganda warfare. The U.S. government issued an ultimatum to Germany to sever diplomatic relations, and Germany had to announce that it would stop sinking unresisting merchant ships without warning, known as the "Sassetex Guarantee".

As the situation of the war changed, on February 1, 1917, Germany once again resumed its most effective trump card of naval warfare, unrestricted submarine warfare, and pushed submarine technology to its peak. Germany judged that even if the United States entered the war, it would take a year and a half for the American army to be formed and transported to Europe, and whether it could be transported to Europe under the blockade of German submarines was another matter, and Germany only needed to end the war before the Americans came. The Germans were always overconfident in their ability to fight against each other, and did not hesitate to take strategic risks.

On 25 February, Wilson received a secret telegram from Ambassador Pécs to Britain, with a top-secret telegram from German Foreign Minister Zimmermann to the German ambassador to Mexico on 19 January.

"We intend to begin unrestricted submarine warfare on February 1st, and in the meantime we will endeavour to keep the United States neutral, and if we fail to do so, we intend to form an alliance with Mexico on the basis of concerted operations, peace treaties, generous financial assistance, and our acquiescence to Mexico's recovery of lost territory in Texas, New Mexico, and Arizona, the details of which are arranged by you, and we are expected to go to war with the United States," Zimmerman wrote in the telegram. Your Excellency shall immediately and secretly convey to the President of Mexico and ask him to take the initiative to invite Japan into the war and to regulate the relations between Japan and us. Tell the President that unrestricted submarine warfare will force Britain to make peace within a few months. Please reply to the call. - Zimmerman".

The effect of this cable, which not only admits to fighting the United States, but also extends its hand to Mexico, which the United States regards as its backyard, was undoubtedly explosive, and the British made it the front page of The Times.

Seeing the enraged American people, Wilson certainly would not let go of this opportunity. On March 12, Wilson bypassed Congressional authority for the State Department to declare armed merchant ships sailing in the war zone, which could fire on German submarines.

A few days later, three more ships, "Memphis City", "Illinois", and "Virginia", were sunk, and the call for war was getting louder and louder. Then, on March 15-18, the U.S. Congress voted to declare war on the Allies under the slogan "Fight for democracy, freedom, and American money."

Eder watched for a maximum of ten seconds after receiving information about the declaration of war by the United States, and now it seemed to him that the United States had no direct influence on Romania. Because now an incident in Russia has the most direct effect on Romania.