There are three major reasons:
The United States. If you meant which National Crisis its hard to say, he created so many of them from the Iranian Hostage Crisis to the Economic Crisis.
declare a bank holiday that closes banks for days
There was a worldwide energy crisis in the 1970s. Watergate was a significant political scandal and the Iran Hostage Crisis were significant events in the United States. The Vietnam War persisted through the first 5 years of 1970.
The United States debated about if they should bring the Shah into the U.S. for medical treatment. Or if they should listen to demands the Iranians wanted.
The United States released a large number of frozen Iranian funds in Western Banks in exchange for the Hostages. To find out more, see the link below.
You will understand that the United States government has acted as much as it could to lessen the credit crisis. You will also know that the United States government has had a limited impact on actually reversing the credit crisis.
In 1933
The United States refused to render the deposed Shah of Iran back to Iran for trial (and likely execution) at the hands of the new Islamic Republic regime.
The origin of the Financial crisis was in the United States.
on march 5
The country that faced the missile crisis was the United States.
In the United States, only a joint resolution of Congress can officially declare war.