The UK has always tolerated greater intrusion by the government into what Americans would consider privacy, press, or assembly freedoms. I suggest you explicitly acknowledge this difference to avoid having your commentary discounted. Specifically regarding terrorism, terrorism is part of most people's experience in England. Bombings appear regularly on the news. Most people have been somewhere that a bomb has subsequently gone off.
Most people know somebody who has experienced a bombing.
Thus, I'd rephrase your material on the threat of terrorism to acknowledge the threat and explain why key escrow will have little impact. British intelligence has been subject to penetration by foreign intelligence moles to an even greater extent than American intelligence has. Moles in the UK have included not only senior intelligence officials, but also secretaries and clerks with access to information similar to escrowed keys. As more and more espionage is directed towards aims that are explicitly commercial or have commercial flavor, escrowed keys of UK firms become an increasingly attractive target for foreign intelligence services. I don't know exactly how much the UK plan resembles the flavors of Clipper, but Clipper contained, IMHO, a Trojan horse literally hidden in plain view.