Secretary Root spoke of the Platt Amendment as supplying a basis in international law for intervention by the United States under the Monroe Doctrine to protect the independence of Cuba. But with how much justice or logic could the United States enforce the Monroe Doctrine against European intervention in turbulent Western Hemisphere republics if it took no responsibility for the behavior of such republics or for the fulfillment of their obligations to Europe? The Platt Amendment, by restricting the debt-contracting power of Cuba and permitting the United States to intervene for the preservation of orderly government, hinted that the Monroe Doctrine involved certain policing responsibilities for the United States. That idea, though previously suggested from time to time, was now for the first time written into law. Need for such a principle was emphasized by events in Venezuela in 1902–1903.
In 1901, when the German and British governments were contemplating the use of force to collect debts from the Venezuelan dictator, Cipriano Castro, Theodore Roosevelt (then vice president) wrote to a German friend: "If any South American country misbehaves toward any European country spank it." In his first annual message as president a few months later he declared that the Monroe Doctrine gave no guarantee to any state in the Americas against punishment for misconduct, provided that punishment did not take the form of acquisition of territory. When, however, in the winter of 1902–1903, Germany and Great Britain actually undertook to bring Castro to terms by a "pacific blockade," anti-German sentiment flared up in the United States, and Roosevelt became alarmed over the possibility that such a situation might produce a serious quarrel between the United States and some European power. The Venezuelan crisis was settled when Castro agreed to submit the question of his debts to arbitration, but no one knew when Venezuela or one of its neighbors might present a new invitation to coercion. It seemed to Roosevelt desirable to find a formula by which all excuses for European intervention in the New World might be removed.
The formula was announced by Roosevelt in 1904, first in May in a letter to Secretary Root, then, in almost identical language, in his annual message of 6 December 1904. As stated in the annual message:
Any country whose people conduct themselves well can count upon our hearty friendship. If a nation shows that it knows how to act with reasonable efficiency and decency in social and political matters, if it keeps order and pays its obligations, it need fear no interference from the United States. Chronic wrongdoing, or an impotence which results in a general loosening of the ties of civilized society, may in America, as elsewhere, ultimately require intervention of some civilized nation, and in the Western Hemisphere, the adherence of the United States to the Monroe Doctrine may force the United States, however reluctantly, in flagrant cases of such wrongdoing or impotence, to the exercise of an international police power.