The irony of the moment was unmistakable. On the evening of April 2, 1917, President Woodrow Wilson delivered one of the most famous addresses in U.S. history; he asked Congress to recognize that a state of war existed between the United States and Germany. Only five months before, he was re-elected, with many of his supporters chanting, "He kept us out of war." Now he asked Congress to sanction entry into a war of unprecedented dimension. How did this great reversal happen? Wilson had fended off continuing affronts to the country's neutral rights for nearly three years. British excesses in imposing its naval blockade of Germany and neutral Europe – and Germany's use of submarine warfare – had repeatedly tried the patience of Americans and their president. Several times, Wilson's diplomacy had pulled the country back from the brink of war, sometimes to the dismay of his more bellicose countrymen. War seemed certain in 1915, when a German U-boat sank the British passenger liner Lusitania on May 7; 128 American passengers died. Still, Wilson managed to defend U.S. neutrality. On March 24, 1916, a German submarine torpedoed the Sussex, an unarmed English Channel steamer, causing 80 casualties and injuring several Americans. Wilson threatened to sever diplomatic relations with Germany unless it abandoned submarine warfare against passenger and merchant ships. Germany complied with the "Sussex Pledge" and agreed not to attack unresisting merchant vessels without warning – provided that Washington pressure London to observe international law while imposing its blockade. The pledge held. By the November 1916 presidential election, German-American relations were calm but estrangement with Britain had grown. Wilson was frustrated by British resistance to his attempt at mediating an end to the war. Furthermore, he shared widespread American resentment of severe measures Britain used in April to suppress the Irish uprising in Dublin, and its blacklisting of 87 U.S. firms suspected of trading with the Central Powers. Nevertheless, Wilson renewed his efforts to mediate the war after his re-election; the longer this titanic struggle went on, the more difficult it became to preserve U.S. neutrality. The president felt the belligerent powers might find 1916 an opportune time to end the war. During that year, the pendulum of war had swept back and forth across the Western Front, but two of history's epic battles – Verdun and the Somme – left the battered armies deadlocked. Both sides suffered huge losses, and rumors spread that they were exhausted. Before Wilson could issue his call for mediation, German Chancellor Theobald von Bethmann Hollweg took independent action. On Dec. 12, he proposed a conference between the Central Powers and the Allies to discuss peace terms. The German peace move was, in fact, Bethmann Hollweg's last chance to provide an alternative to Berlin's resumption of all-out submarine warfare, which the German High Command was then considering. Despite the stalemate on the Western Front, peace at this time could benefit Germany. Its armies occupied most of Belgium and northeastern France, and its recent campaign in Rumania had been highly successful. The High Command believed Germany could negotiate from its position of relative power, but there was no guarantee about how long its favorable position would last. In his communiqué to the Allies, Bethmann Hollweg indicated his government was willing to negotiate to end the ravages of war, now that their "indestructible strength" had won "considerable successes at arms," which justified hope for yet others in the future. Berlin's announcement caused Wilson to hesitate in launching his own initiative. Would his planned invitation to the belligerents to discuss peace terms suggest he was acting in collusion with Germany? He decided to risk being misinterpreted, and sent identical notes to the warring powers Dec. 18. In an effort to disassociate his note from the German peace proposal, Wilson assured the powers that he was proposing neither peace nor mediation. Instead, he invited them to state their war aims in a manner that might lead to a conference. He added that the United States was eager to cooperate in the restoration of peace, and in the formation of a league of nations to secure it. Germany answered for the Central Powers, saying they preferred direct negotiations between the opponents and declined to state any specific terms. The work of preventing future wars could be taken up after the present one was over. The Allies considered this an evasive response and used it as a reason to reject the German peace discussion offer of Dec. 12. They also took the opportunity to respond more fully than the Central Powers to the president's request for a statement of war aims. Britain answered for the Allies, saying their objectives included the evacuation of occupied territory, the payment of indemnities, and the liberation of the subject nationalities of Central Europe from alien domination. That was more than the Central Powers had any intention of accepting. In fact, neither side favored a compromised peace at this time. Wilson's hopes for mediation soon suffered another setback. After the content of the German note became known, Johann von Bernstorff (the German ambassador in Washington) met with Col. Edward M. House, Wilson's closest adviser. The ambassador had been disappointed with Berlin's reply to Wilson and broached the subject of confidential negotiations that could lead to a peace conference. Of course, negotiations could not proceed before the German terms were known, and when House and Wilson received them Jan. 15, they proved more liberal than expected. However, Bernstorff informed them several days later that U.S. participation would not be welcomed at the peace conference, even if Wilson were successful in arranging it. Only belligerent powers would attend the conference to agree on peace terms. American participation, of course, would be welcomed at a later general conference that would address reconstruction of the international order. The president's hopes for mediation could not have been dealt a harder blow. Nevertheless, Wilson moved to a second step in his peace initiative. He chose to tell the world what he believed should be the general terms of a peace settlement the United States would join in upholding. On Jan. 22, 1917, he appeared before the Senate and delivered what some historians consider his greatest address. The Peace Without Victory speech was a synthesis of liberal hopes for a lasting peace settlement. It would be a peace among equals, without annexations and indemnities, and one that provided a league of nations to guarantee permanent peace. The address elicited huge responses on both sides of the Atlantic. Liberals everywhere called it epochal. Conservatives were more restrained. Some dismissed it as impractical, even presumptuous. Regardless, Wilson's efforts to mediate the war were fated to fail. Two weeks before his address, the German High Command convinced Emperor Wilhelm II to resume unlimited submarine warfare on Feb. 1, 1917. It was questionable how long Germany could maintain its vast war efforts, and its High Command still hoped for a decisive military victory that would ensure favorable peace terms. With stalemate on the Western Front, the defeat of Britain was key to a German victory. Only by resorting to unrestricted submarine warfare could Britain be defeated. The order applied to all neutral and belligerent ships that entered designated, broad war zones in seas crucial to Germany's enemies. According to the High Command's calculations, all-out submarine warfare could reduce the British to starvation within five months. Germany's military leaders realized the order might – probably would – provoke U.S. intervention, but they dismissed that possibility as irrelevant. Compared to the huge armies engaged on European battlefields, the U.S. Army seemed small: 107,641 men and 132,000 National Guardsmen (plus 15,500 U.S. Marines deployed mostly overseas). The High Command reasoned that the war would be over before the United States could raise, train and transport to Europe an army large enough to be of consequence. "From a military point of view, America is as nothing," German Naval Minister Eduard von Capelle assured a Reichstag leader who questioned the order. It was a gamble that proved to be the most fateful miscalculation of the war. News of the order shocked Wilson and the entire nation. Here was Germany's answer to the Peace Without Victory speech and to mediation, which had never been a serious part of Germany's calculations. Germany had scrapped the Sussex Pledge and insulted America's neutral rights and national honor beyond measure. The president severed relations with Germany but hesitated to go further, unless German U-boats attacked U.S. ships. The responsibility for whatever dire consequences might follow would be on Germany. In retrospect, the publication of the German order marked a great divide in German-American relations. For months, attention had been focused on mediation and peace. But now, war and darker times seemed imminent. On Feb. 25, 1917, Wilson learned of the Zimmermann telegram. In this famous intercepted communiqué, German Foreign Secretary Arthur Zimmermann invited Mexico to enter an alliance with Germany, should war occur between it and the United States. For joining with Germany, Mexico would receive "ample financial support" and, pending victory, the return of lost territory in Texas, New Mexico and Arizona. When the Zimmermann note was published March 1, it stunned the American people, especially several days later when the author verified its authenticity. Newspapers across the country labeled it a "villainous" plan and an unmasking of Germany's real intentions. Americans resigned themselves to the fact that war was near. At the same time, news arrived that a German submarine had sunk without warning the British passenger liner Laconia. Two Americans were lost. Wilson ordered U.S. merchant ships and passenger liners to be armed. Still, he agonized, hoping that war could somehow be avoided. In the midst of his struggle to determine the right course to follow, encouraging news arrived. A liberal group in the Russian parliament had overthrown Czar Nicholas II, established the new Provisional Government, promised a new constitution, and declared its intention to stay in the war. All along, the Western Allies professed to be fighting a war for democracy against autocracy, but Russia's repressive government called that claim into question. Some Americans feared Russian despotism more than German militarism, but now those fears were allayed. There was, however, little time to savor the good news. On March 18, reports arrived that U-boats had sunk three U.S. merchantmen; on one, 15 crewmen perished. Armed neutrality had failed to deter German submarines. Two days later, Wilson convened the most important cabinet meeting of his presidency to discuss the emergency, only to learn that his colleagues saw no alternative to war. Several believed that a state of war already existed. Afterwards, the president called a special session of Congress for April 2. To ponder the greatest decision a president must face, Wilson retreated from public view. The White House remained silent about the paramount question: would there be war? But the country was not silent. Huge demonstrations for war occurred in major cities. Former president Theodore Roosevelt and other Republican party leaders adopted a resolution declaring that "war now exists." Numerous newspapers heralded the same message. The opponents of a military solution also conducted mass meetings and petitioned Wilson to resist taking the country to war. Their protests were formidable, but the nation's majority opinion now tilted against them. It was still conceivable that Wilson might decide against intervention. As he had said on previous occasions, he would not rush into war. The decision was his to make and, as the world learned on the evening of April 2, he made it in favor of war. Early in January, while writing his Peace Without Victory speech, Wilson told his adviser, House, "There will be no war." Now, three months later, he decided there was no alternative to war, short of acquiescing to Germany's terms. Germany had rejected mediation to end the war, hoping to achieve victory by force of arms. Its intransigence over using unrestricted submarine warfare remained unabated. Wilson had his doubts about the Allies' motives in the war, but German U-boats were destroying American life and property. Moreover, he had come to realize that Germany's leaders could not be trusted and believed they wished to establish a new balance of power after the war. They had become, in fact, an obstacle to the establishment of a just and lasting peace, and to the creation of a postwar community of nations worthy of U.S. support and participation. The only record Wilson left of his great reversal from peace to war was the explanation he gave in his April 2 address to Congress. In that memorable speech, he focused on Germany's resumption of unrestricted submarine warfare. He said that act convinced him that Berlin's "autocratic government" could not be trusted. It had disregarded international law, trampled on the rights of neutral nations, and engaged in a war against all nations. The German government, Wilson continued, had forced war on the United States by attacking its citizens on the high seas. Unwilling to "choose a path of submission" to conditions Germany imposed, the president avowed the nation would fight to defend its rights and honor. But it would not fight for that alone. Germany's recent actions proved there could be no "assured security" for democratic nations without the defeat of German power and all it had come to represent. Germany had become a menace to world peace and to "the freedom of its peoples." The United States would fight as a champion for the rights of mankind "to make the world safe for democracy." It would fight for the creation of a "concert of nations." Since no autocratic government could be trusted to keep its covenants, a partnership of democratic nations would provide a durable peace and defend the "interests of mankind." To these ends, he asked Congress to commit the full force of the United States. James D. Startt is a senior research professor in history at Valparaiso University.