Yes there have been successful interceptions.
Which system are you referring to?
You've got:
Patriot
Patriot was deployed to Iraq in 2003, this time to provide air and missile defense for the forces conducting Operation Iraqi Freedom (OIF). Patriot PAC-3, GEM, and GEM+ missiles both had a very high success rate, intercepting Al-Samoud 2 and Ababil-100 tactical ballistic missiles.[29] However, no longer-range ballistic missiles were fired during that conflict. The systems were stationed in Kuwait and Iraq successfully destroying a number of hostile surface-to-surface missiles using the new PAC-3 and guidance enhanced missiles.
https://en.wikipedia.org/wiki/MIM-104_Patriot
Aegis Combat System
Since 2002, a total of 19 SM-3 missiles have been fired in 16 different test events resulting in 16 intercepts against threat-representative full-size and more challenging subscale unitary and full-size targets with separating warheads. In addition, a modified Aegis BMD/SM-3 system successfully destroyed a malfunctioning U.S. satellite by hitting the satellite in the right spot to negate the hazardous fuel tank at the highest closure rate of any ballistic missile defense technology ever attempted.
https://en.wikipedia.org/wiki/RIM-161_Standard_Missile_3#Missile_defense
Terminal High Altitude Area Defense (THAAD)
22 November 2005 Success Launched a missile in its first Flight EMD Test, known as FLT-01. The test was deemed a success by Lockheed and the Pentagon.
11 May 2006 Success(?) FLT-02, the first developmental flight test to test the entire system including interceptor, launcher, radar, and fire control system.
12 July 2006 Success FLT-03. Intercepted a live target missile.
13 September 2006 Aborted Hera target missile launched but had to be terminated in mid-flight before the launch of the FLT-04 missile. This has officially been characterized as a "no test."
Fall 2006 Cancelled FLT-05, a missile-only test, was postponed until mid-spring 2007.
27 January 2007 Success FLT-06. Intercepted a "high endo-atmospheric" (just inside earth’s atmosphere) unitary (non-separating) target representing a "SCUD"-type ballistic missile launched from a mobile platform off Kauai in the Pacific Ocean.
6 April 2007 Success FLT-07 test. Intercepted a “mid endo-atmospheric” unitary target missile off Kauai in the Pacific Ocean. It successfully tested THAAD's interoperability with other elements of the MDS system.
27 October 2007 Success Conducted a successful exo-atmospheric test at the Pacific Missile Range Facility (PMRF) off Kauai, Hawaii. The flight test demonstrated the system's ability to detect, track and intercept an incoming unitary target above the Earth's atmosphere. The Missile was hot-condition tested to prove its ability to operate in extreme environments.
27 June 2008 Success Downed a missile launched from a C-17 Globemaster III.
17 September 2008 Aborted Target missile failed shortly after launch so neither interceptor was launched. Officially a "no test"
17 March 2009 Success A repeat of the September flight test. This time it was a success.
11 December 2009 Aborted FTT-11: The Hera target missile failed to ignite after air deployment and the interceptor was not launched. Officially a "no test".
29 June 2010 Success FTT-14: Conducted a successful endo-atmospheric intercept of unitary target at lowest altitude to date. Afterward, exercised Simulation-Over-Live-Driver (SOLD) system to inject multiple simulated targets into the THAAD radar to test system's ability to engage a mass raid of enemy ballistic missiles.
5 October 2011 Success FTT-12: Conducted a successful endo-atmospheric intercept of two targets with two interceptors.
24 October 2012 Success FTI-01 (Flight Test Integrated 01): test of the integration of THAAD with PAC-3 and Aegis against a raid of 5 missiles of different types. During this engagement THAAD successfully intercepted an Extended Long Range Air Launch Target (E-LRALT) missile dropped from a C-17 north of Wake Island. This marked the first time THAAD had intercepted a Medium Range Ballistic Missile (MRBM). Two AN/TPY-2 were used in the $180m test, with the forward-based radar feeding data into Aegis and Patriot systems as well as THAAD.
https://en.wikipedia.org/wiki/Terminal_High_Altitude_Area_Defense
"I have never seen anything showing that a true test, where a bogie is sent at an unknown time from an unknown place, has worked"
Generally it's a bad idea to fire ballistic missiles at nuclear armed countries without some warning unless you are looking to accidentally start WWIII.
= new reply since forum marked as read
as the actual policy.
