A good article for discussion around protectionist policies https://www.straitstimes.com/business/economy/china-manufacturing-slows-in-september-as-trade-war-worsens
See below where to find the relevant section within the specification for A Level Economics:
Edexcel spec reference 4.1.6 c) Impact of protectionist policies on consumers, producers, governments, living standards, equality
AQA spec reference 188.8.131.52 The causes and consequences of countries adopting protectionist policies.
OCR spec reference P25 explain the impact of methods of protectionism