Martin's suggested intro, tweaked

draft-ietf-quic-transport.md

@@ -6421,11 +6421,10 @@ the CONNECTION_CLOSE frame with a type of 0x1d ({{frame-connection-close}}).
 
 # Security Considerations
 
-The goal of QUIC is to provide a secure transport connection.  However,
-third-parties and malicious peers are able to disrupt the connection in
-various ways.  {{security-properties}} presents an in-depth overview
-of the security properties QUIC attempts to provide; subsequent sections
-discuss the mitigations QUIC employs against various types of attacks.
+The goal of QUIC is to provide a secure transport connection.
+{{security-properties}} provides an overview of those properties; subsequent
+sections discuss constraints and caveats regarding these properties, including
+descriptions of known attacks and countermeasures.
 
 ## Overview of Security Properties {#security-properties}