The Nixon Doctrine was applied while the Vietnam War was still underway and was used to draw out American troops in an attempt to bring down the body count. American troops were pulled out and were replaced by the Vietnamese troops. By doing so, the American government responded to increasing insecurities and reservations that the American public was beginning to show towards American presence in the Vietnam War and the losses it was incurring as a result of the same.
The Middle East Crisis in the 1970s saw the US revisit the Nixon Doctrine in a fashion similar to that in which it had assisted Israel earlier. The US did not physically intervene and did not take any direct part in the crisis but ensured that its interests remained unharmed by providing financial and military support to its allies.
President Richard Nixon and National Security Adviser Henry Kissinger considered the Nixon Doctrine to have been successfully implemented since it allowed them to continue battles on multiple fronts. Under the protection of the Nixon Doctrine, the United States had the advantage of being able to fight its own wars, while indirectly weakening its enemies by assisting its allies in their battles. Also, the application of the Nixon Doctrine allowed the US military to be drawn out of Vietnam so that it could be brought into use to penetrate Laos.