When thinking about the qualities of great leaders we might use terms like vision, ambition, discipline, and inspiration. But leadership is also about restraint and knowing when to quit.

As a young Navy SEAL, my first combat deployment was to Iraq in the spring of 2003. No one in my platoon had any combat experience. Before moving into Iraq we spent a few weeks of preparation at Ali Al Salem Air Base in Kuwait.

While at the air base, we were tasked with our first mission. Intel came down that retreating Iraqi forces were planning to destroy a hydroelectric power plant and dam in order to slow the American advance. Our assignment was to fly from Kuwait to Northern Iraq, take control of the dam and await further assistance from conventional military forces. My platoon would assault, clear and take control of the power plant while SEAL mobility teams and Polish Special Forces would secure the buildings along the perimeter of the property.

One of the key complications was the distance of the flight for insertion to the target. The weather had to be perfect. And although time was of the essence, our leaders decided to abort the mission three times in a row. It is incredibly stressful sitting in a helicopter on the tarmac with the blades spinning only to then hear that the mission is getting postponed 24 hours. On the third day, we got the green light and the mission was a success. Most good leaders have the drive to keep pushing forward and tackling new obstacles. Great leaders also practice restraint when necessary.

Here are four signs that it's time to quit and rethink the plan.

1. You haven't done your due diligence.

It's not uncommon that an organization will move forward with a new project, customer or strategy without having taken the time to plan accordingly. As a young entrepreneur, I remember every opportunity sounding great. The fact that a customer wanted to work with us or another company was interested in a strategic partnership was flattering. But now, as a more seasoned business owner and leader, I understand that selecting the right opportunities that align with your vision and goals is critical. Not doing so costs you money. Every single time.

2. You don't have the full support of your team.

Great leaders assemble the right team. Then they obtain full (or at least majority) buy-in from the team before moving forward with the mission plan. The team will be the group executing the plan, and therefore must take ownership. If they don't believe in the cause or strategy, your chances of failure skyrocket.

In the SEAL teams the way leaders get buy-in from all stakeholders is to have good data, a great plan, and an even better contingency plan. As the saying goes, "NO plan survives first contact with the enemy."

3. External forces are working against you.

In that first mission, the weather delayed us again and again. But had we moved forward with the plan when all of the elements were not in line, the potential for failure would have been very high. And failure in combat can mean injury or death.

In business, it is the responsibility of the leadership to identify what external forces are working against you, and either remove those obstacles or abort the mission and reset the plan.

4. The costs outweigh the benefits.

Managing cost benefit ratios is a basic function of good business. Is taking this action going to have benefits that exceed the cost of the investment? Will this plan generate a positive ROI? This could mean investing in new talent that has a higher salary requirement than you want to pay. It could mean large upfront costs for new technology that will make you more efficient down the road. Great leaders use the data they have at hand in order to make the best possible decision. They also learn from past mistakes and quickly identify when a decision will not have a beneficial outcome. That's when they abort the mission.

Restraint doesn't always come easy to great leaders and successful people. But taking the time to have a good plan, get buy-in from the team, and measure the potential outcome will save you the headache (and costs) of making the wrong decision.