Let's frame it this way: Can the police pay criminals to commit crime in order to arrest other people?
Here is a lovely example of my own wealthy first world country scamming one of the poorest nations on earth out of their oil reserves for a handsome profit. The man (Nick Warner) behind it all lives in luxury guarded by guns and the bureaucratic evil protecting him and his ilk. The minister at the time (Alexander Downer) afterwards went on to work for Woodside Petroleum, one of the biggest oil companies in the world who coincidentally was the main beneficiary of the shady deal.
May history judge them all appropriately.
https://en.wikipedia.org/wiki/Australia–East_Timor_spying_sc...
"Play both sides, for power." Now, the UK is freely admitting it does this.
The influence of one over the other and vis versa seems convincing.
I could tell you more but then I would have to kill you.
It seems the entire discussion here is based on a misunderstanding, the vast difference between what MI5 calls an "agent" and what the public understands when we hear "an MI5 agent", and thus misses the point by about a mile?
There's an interesting debate to be had about the questions posed by the article, it's just not what's being discussed here right now. For example, in Germany, an attempt to have the far-right ultra-nationalist NPD banned for being anti-constitutional in 2003 was rejected by the Federal Constitutional Court because a large number of agents (called V-Männer in German) were active in the party leadership. This raised the question of whether some of the evidence against the party might actually be influenced by agents of German secret services. Since the secret services did not want to fully disclose their agents' identities and activities, the court found the case to be impossible to decide.