If you are looking at ICBM/IRBM defence against a limited attack, then the you want forward based up threat radars such as the AEGIS site planned for Poland. NATO also has a contract for integrating BMD into C2 systems*
Fylingdales might come into that, but I can’t see us building more radars, and we are too far back to host missiles.
*
https://www.prnewswire.com/news-rele...301541829.html