Would you join to fight for the imperialists ? To join you just have to show up at a recruitment center in France, i even saw an illegal Russian immigrant get recruited and also a Kenyan in the docu below ( subtitles are shit though ), but the selection process is very competitive. The french foreign legion has existed for centuries where france recruits foreigners to fight for them.
Their training and missions are some of the hardest. Most quit in the first 2 weeks
They are a kind of special forces so you can’t expect less. Their pay is attractive if converted to Kenyan currency.