Divide and Conquer is perhaps one of the most famous strategies to gain power. On the outset everyone seems to understand it. Numerous examples in history show that this strategy is indeed effective.

Robert Greene described this strategy beautifully: 

"Never be intimidated by enemy's appearance. Instead, look at the parts that make up the whole. By separating the parts sowing dissension and division, you can bring down even the most formidable foe. When you have troubles or enemies, turn a large problem into small eminently defeatable parts." 
This strategy can be applied to many different situations.

When in competition

A classic example for this situation is when you are playing Risk and are confronted with a bigger foe. Your opponent might be stronger than you, but there is no reason why you can't beat him if not too late. Here are some options for the Risk strategy:

• Alienate him from his allies. An isolated opponent is easier to tackle.

• Divide his empire into parts. Attempt to conquer them one at a time. Conquering the parts will be easier and more manageable for you. It will also help you psychologically as you will no longer feel you have to fight a mighty foe.
  

• Turn his allies against him. Propaganda, diplomacy and a bit of imagination can go a long way. As seen on Hollywood movies, the bad guys always turn to each other when they want to share the prize. Exploit the human ego to your benefit. 
  

When confronted with a huge task

Sometimes you may find yourself confronted with a huge task at hand. The sheer size of the job may make you feel hopeless and the task unachievable. Here is an interesting story:

"Thirty years ago my older brother, who was ten years old at the time, was trying to get a report on birds written that he had three months to write. It was due the next day. We were out at our family cabin in Bolinas, and he was at the kitchen table close to tears, surrounded by binder paper and pencils and unopened books on birds, immobilized by the hugeness of the task ahead. Then my father sat down beside him, put his arm around my brothers shoulder, and said, Bird by bird, buddy. Just take it bird by bird."

The above is from Bird by Bird: Some Instructions on Writing and Life by Anne Lamott. She beautifully captures the essence of the solution. If you think the task is big, you need to dissect it to pieces in your mind.

When overwhelmed by the world and events

Today's world is progressing at a higher pace. There is simply a lot more than can be done and that means we all want to do more. Time is limited and as a result people are more conscious of time and the huge number of events taking place everyday. Managing all this can become overwhelming and you need to keep your head clear of all this.

No matter what it is, you can look at it as en entity consisting of multiple parts. Be it the world, the project, the Risk opponent, your wedding, ... anything. Once you have identified the entity, divide it into parts. You can examine each part separately and tackle the smaller ones first. As you take down more parts, the problem becomes easier to handle. Always be in command of your own brain, or else you will be at the mercy of the task.