1. Capitalists are in competition with each other.
2. One way they try to resolve this is to cut production costs.
3. One way they do this is to automate.
4. Automation and robotics are expensive. This threatens 'profitability' ie how much profit per invested pound they can make per worker.
5. But they have to do it.
6. But this means laying off workers. ('efficiency')
7. Unemployed or under-employed (zero hours and 'self-employed) workers earn less, which means they buy less.
8. In other words they can't buy what the robots make.
9. This is a crisis.
10. Solution 1 - capitalists invest in speculative rubbish instead of 'production' - this leads to 'bubbles' like bank crash of 2008.
11. Solution 2 - roam round the world looking for labour, markets and raw materials to seize.
12. Snag: this can lead to war.
13. Shouting 'America First' and getting allies to agree on the grounds of 'freedom' or 'smashing the bad guys' etc is very useful.
14. Further snag for human beings: death, destruction, mayhem, endless attacks, terror, tragedy.