The important thing to remember is that wins are counted on a "per-player basis," and aren't dependent on using a Clan vs. Clan playlist. If you're in a Clan then you're already fighting the good fight.
Infinity goes on to detail how nodes are captured, defended and what happens when its lost. They wanted the pressure to mount if you start capturing nodes across the map.
"The primary objective of Clan Wars is to earn as many Capture Points (CP) as possible throughout the Clan War. Capture Points are earned when your Clan captures any of the 10 nodes or locations on the Clan Wars map. Your Capture Points continue to add up as you capture more nodes and you will not lose them if you lose control of that node. The winner at the end of the Clan War is the Clan with the most Capture Points," Infinity Ward.
If your Clan teams up in playlists designed to lead to a nodes capture then more points are awarded as opposed to going it solo. These nodes give special bonuses while they're held such as XP boosts. Once the threshold is met to capture the node then your Clan has the choice of 'staying to defend' or leaving for another.
As other Clans try to take the node from you the score you racked up to take the node in the first place is eroded and so if it isn't topped back up you'll lose the node. Infinity Ward also coded a maximum number of wins allowed to ensure the nodes remain competitive, so a Clan can only hold out for so long.
Check out theby Infinity Ward for more in Clan Wars nodes.