Often, some of the following factors can contribute to these failures:

• A conservative and traditional attitude, often marked by the misuse or rejection of newer technology and the inability to learn from experience.
• Rejection of information which challenges preconceptions.
• Overestimating the abilities of one's own side and underestimating those of the enemy.
• Indecisiveness and the inability to consider swift action, marked by a failure to exploit battlefield gains.
• Over-persistence.
• Frontal assaults and brute force over surprise, deception and/or tactical skill.
• In defeat, the search for scapegoats and the suppression of information.
• A belief in fate or luck rather than a rational assessment.

Further reading: