From Moon of Alabama:

Last night the Yemeni army launched (vid) seven ballistic missiles against Saudi Arabia. Three of those targeted the capital Riyadh, four were aimed ar military and infrastructure targets. In Riyadh the Saudi forces fired a a number of Patriot surface-to-air missiles and claimed that those successfully intercepted the Yemeni missiles. The Saudis Patriot Advanced Capabilities-2 system (PAC-2) are made by the U.S. company Raytheon which is also hiring former U.S. soldiers as ‘Patriot Battery Systems Technician Field Engineers’ to man and maintain the Saudi systems.

Earlier Saudi claims of successful intercepts turned out to be false. The small warheads of the Yemeni missiles separate from the larger missile body and are difficult to detect. The U.S. provided systems inevitably aims at the bigger empty missile body…

Last year the Saudis were pushed by the Trump administration to buy the new Terminal High Altitude Area Defense (THAAD) missile defense system:

The package that cleared Friday would include 44 THAAD launchers, 360 interceptors, 16 THAAD Fire Control and Communications Mobile Tactical Station Groups and seven AN/TPY-2 THAAD radars, along with associated support equipment and training.

This new system is supposed to defend Saudi Arabia against Iranian ballistic missiles. But according to a South-Korean analysis the THAAD missile defense system has the same problem the Patriot system has. It can easily be deceived by cheap decoys and it tends to hit the incoming missile body while missing the separate warhead which simply continues its attack on the target.

From Wikipedia:

“The W47 is the only US ICBM or SLBM warhead to have been live fired in an atmospheric missile and warhead test, on May 6, 1962.”

From Michael Lewis:

[T]he United States no longer tests its nuclear weapons. Instead, it relies on physicists at three of the national labs—Los Alamos, Livermore, and Sandia—to simulate explosions, using old and decaying nuclear materials.

From The Heritage Foundation:

[T]he U.S. has elected to maintain nuclear warheads—based on designs from the 1960s and 1970s—that were in the stockpile when the Cold War ended rather than take advantage of technological developments to field new warheads that could be designed to be safer and more secure and could give the United States improved options for guaranteeing a credible deterrent.