Executive agreements are international agreements made by the President of the United States without the approval of Congress. While these agreements are a useful tool for quickly negotiating and implementing foreign policy, they are not without limits. Here are some of the key limitations on executive agreements:

1. They cannot contradict existing federal law.

Executive agreements cannot override or amend existing federal law. If an executive agreement conflicts with a federal law, the law takes precedence. For example, if an executive agreement attempted to legalize an activity that is prohibited by federal law, the agreement would be invalid.

2. They cannot violate the Constitution.

Executive agreements must also comply with the Constitution. If an executive agreement violated the Constitution, it would be struck down by the courts. For example, if an executive agreement attempted to establish a national religion, it would be unconstitutional and therefore invalid.

3. They cannot infringe on the powers of Congress.

Executive agreements cannot infringe on the powers granted to Congress by the Constitution. If an executive agreement attempted to take away powers that belong to Congress, it would be invalid. For example, if an executive agreement attempted to transfer the power to declare war from Congress to the President, it would be unconstitutional and therefore invalid.

4. They must be within the scope of the President`s authority.

Executive agreements must also be within the scope of the President`s authority. If an executive agreement exceeded the President`s authority, it would be invalid. For example, if an executive agreement attempted to regulate domestic commerce, it would be outside the scope of the President`s authority and therefore invalid.

5. They are subject to change by future Presidents.

Finally, executive agreements are subject to change by future Presidents. Unlike treaties, which require the advice and consent of the Senate and can only be terminated by mutual agreement, executive agreements can be terminated by the President at any time. This means that an executive agreement made by one President may not necessarily be upheld by the next President.

In conclusion, while executive agreements can be a valuable tool for implementing foreign policy, they are subject to certain limits. These limits ensure that executive agreements do not violate federal law or the Constitution, infringe on the powers of Congress, or exceed the President`s authority. Additionally, executive agreements are subject to change by future Presidents, which means that their longevity is never guaranteed.