How we change what others think, feel, believe and do
Kill With a Borrowed Knife
This stratagem number: 3
Get others to do your fighting for you.
Convince them that your enemies are their enemies, and that if they do not join battle then they will be defeated, betrayed or otherwise end up in a very poor position. Feed them information of planned attacks on them. Point to spies in their camp. Highlight the immediate danger to them of your enemies.
A clever way is to let your enemy find 'spies' within their own camp (who are actually people you want dismissed, disabled or destroyed).
You can also work to spark conflict between your enemy and some other party such that they end up fighting. Even if your enemy is not defeated, they will be weakened sufficiently for you to finish the job.
Getting others to fight in your stead can even mean avoiding being on the front line, standing behind your allies and compatriots who will bear the brunt of the initial conflict.
More broadly, you can also seek resources and abilities that others have in a wide range of subjects that you can leverage and use to your advantage.
This is the third stratagem of thirty-six.
Stratagems When Commanding Superiority
Kill With a Borrowed Sword
Borrow a Sword to Attack Another
Borrow One's Hand to Kill
Get Others To Do Your Dirty Work For You
Use the Strengths of Others
Chang Tuo defected from Western Zhou to Eastern Zhou. Minister Feng Chu of Western Zhou first send a 'secret letter' to Chang that make it appear Chang was a spy for Western Zhou. He then send another message to Eastern Zhou that led to the first message being intercepted. Eastern Zhou consequently executed Chang.
The king of Zheng 'buried' under an altar a list of Kuai officials and generals he would reward if Kuai fell. The king of Kuai obtained the list and executed them all. Zheng then attacked and conquered Kuai. Hitler copied this method to get Stalin's best generals removed.
Mercenaries and assassins have long been used as paid alternatives to doing one's own fighting and killing. Significant effort may be included here in distancing oneself from the actions of the people employed.
Borrowing also happens in advertising and publicity where celebrities lend their credibility to endorse products.
While it may seem noble and brave to march out to confront your enemies in a fair and decent battle, war is not won like this. Enemies may have superior forces, and even if they do not, every fight weakens both sides. A wise general avoids conflict wherever possible and uses a range of principles, strategies and tactics, including deception of one's own forces and allies.
A danger with getting others to fight for you happens where they realize they are being deceived by you. This can lead to them turning on you and perhaps even joining your enemy. While warfare is full of deception, including between allies, care should be taken to avoid situations that result in betrayal responses.
A broader principle that can be found here is one of borrowing. You can borrow forces, ideas, principles, strategies and so on. Businesses do this with 'benchmarking', where they seek best practices from friendly non-competitors and 'shamelessly steal' their methods.