Above is the link you need to understand directional theory, if you don't have forever to read up on every detail just make sure you look at the chart at least.
Anyways once you've got the basic idea notice at the bottom its applicaiton to stress and security points... this I find interesting.
The basic principle you can ellicit from this is the following:
Moving Towards Integration
Withdrawn types become Confronting
Confronting types become Embracing
Embracing types become Withdrawn
Intuitively this makes an interesting observation, withdrawn type apparently need to learn to leave their inner worlds and face the world, confronting types need to learn to be less antagonistic and make peace with the world by acceptance, and embracing types need to learn to stop worrying so much about outside expectations and take more time to look within at their own desires.
Moving Towards Disintegration
Withdrawn types become Embracing
Embracing types become Confronting
Confronting types become Withdrawn
Intuitively this also makes an interesting observation, withdrawn types apprently quit worrying about their individualism and inner worlds and simply embrace outside expectations, embracing types reject the expectations they once held high and become rebellious against them, and confronting types lose their fighting spirit and fall into withdrawl
What I find particularly interesting about this, is that these basic observation were not conciously incorporated into the construction of the enneagram personality types nor in the direction theory. This all is a surprising deductive result of the theory, and it matches up well with common experience.
Whats even better is that their is some "flow" to the idea, their is a cycle that can go in two directions...
one is Embracing -> Withdrawl -> Confrontation and that is the flow for Integration
the other is Confrontation -> Withdrawl -> Embracing and that is the flow for Disintegration
No matter what type you are these flows are the same. Its almost like some type of psychological pattern or cycle. The other interesting thing is both of them are complete opposites, its like clockwise and counterclockwise, not matter where you are on the clock if your going to reach 5pm and your going clockwise you MUST pass through 4pm first always and 6pm always comes after. There is no possible way to work it so that you hit 6pm first if your going clockwise, it doesn't matter where you come from. This is the same... if you going to arrive at a healthy state of confrontation, you must first go through a state of withdrawl according to this theory, if you go through a state of embracing first, you will be on the pathway to psychological disintegration.
Of course this interpretation is only a logical extension of this theory, and may not hold up to common observation. In my opinion I think it holds up quite well at first glance.