"Security against defeat implies defensive tactics; ability to defeat the enemy means taking the offensive."
"Defensive tactics" is a term commonly used to describe any technique or tactic employed by an officer to effect an arrest, prevent escape, or overcome resistance. However, you will never accomplish any of these three tasks by being defensive.
Obviously blocking punches, escaping from holds, or preventing a suspect from acquiring your firearm are defensive responses. Although each of these is a critical skill, they will only delay your demise unless you manage seize the offense. Remember that the end result of every use of force incident should be the suspect modeling your "matching silver bracelets." There is nothing defensive about forcibly taking another person's freedom!
Variation of tactics
"In hemmed-in situations, you must resort to stratagem. In a desperate position, you must fight.
There is a time to talk and a time to act. Talking when acting was the appropriate response has lead to the deaths of far too many officers.
In most law enforcement encounters, there is adequate time to attempt to reason with whomever it is that you've contacted. With time on your side, you can consider the many options usually available to help resolve the situation. This is where tactical communication comes into play. If you can "sweet talk" the person you're dealing with into full compliance, life is good.
On the other hand, if the person you're dealing with suddenly points a firearm at you, talking should be the last thing on your mind. You are now in what Sun Tzu describes as a "desperate position" (slight understatement) and your only viable option is to fight, or in this case, shoot.
While I'm certain that I didn't do The Art of War justice, hopefully I've convinced you of it's relevance to modern policing. Pick up a copy and give it a read. I'm convinced that If every officer employed the tenets of this great work, lives would undoubtedly be saved.
Train hard. Stay safe!