There's an old saying: "The real discussion begins once the meeting's over, the decisions have been made and everyone has left the room."
Recently, I saw this in action while strolling through a conference center where a number of different companies had meetings taking place. At a break, all the meeting attendees spilled from the rooms and began to cluster around the coffee and muffin spread. I'm an inveterate eavesdropper, and I like muffins, so I lingered a little, moving from table to table. As I did, it was hard not to notice the pattern: every one of these groups of people were having the same conversation. The exact same conversation.
It didn't matter one iota that these groups were from different companies, they were all whispering some variation of, "the people in that room don't really get it... " "this isn't even a marketing issue... ", "everyone's just waltzing around the issue... ", "it's obvious that this is off track because... ", "they're stuck on tactics and we don't have 'a strategy'... ", "someone needs to have a chat with him/her... ", etc. In three words: destructive, obstructive, corrosive. And for this, someone's buying muffins.
So what does a leader need to do to keep the conversation in the room? The first thing is to look in the mirror and ask her/himself what they are specifically doing to support an open climate for discussion which includes debate, dissent and building on each others thoughts. If you're not consciously working on this, actively drawing people out, making it safe and rewarding the behavior you want, then there's a good chance that the whispers you hear on your way past the muffins are not about how nice you look in your suit.