What sorts of policies were adopted in order to maintain and strengthen US scientific and technological superiority?

After World War II, a new threat and direct competitor emerged, the USSR, inspired the U. S. develop new strategies to remain the global leader in military and technology.

In the late 1970's, the Offset Strategy was Developed with the leadership of then-Under Secretary of Defense Bill Perry, consisting in two main parts:

1 - Investment in basic and robust in research and development (R&D), with a focus in information based technology, like networks to deliver and receive information (Internet precursors). These would improve the country's technologies and enable Technological superiority.

2 - Control and application of the technologies through export and trade route control, like the Arms Export Control Act and the Missile Technology Control Regime, allowing the U. S to provide or deny access to particular technologies on command, once these were totally funded, built and controlled by the country.

The strategy was and enormous success, leading the country into an era of scientific-technological dominance by the U. S, resulting not only in the upper hand during the Cold War, but also birthing early-generation microelectronics, nuclear power and a lot of technologies present in the world today.