Final answer:
To better understand the causes and historical context of Iraq's invasion of Kuwait, the historian should refer to sources that provide specific reasons for the invasion. The Persian Gulf War (1990-91), Desert Shield and Desert Storm, and a Figure showing an Iranian soldier wearing a gas mask during the Iran-Iraq War would be the most helpful sources.
Step-by-step explanation:
The most helpful source for the historian to understand the causes and historical context of Iraq's invasion of Kuwait would be the sources that provide specific reasons for the invasion. Based on the provided information, the sources that explicitly mention the reasons for the invasion are:
- The Persian Gulf War (1990-91)
- Desert Shield and Desert Storm
- Figure: An Iranian soldier wearing a gas mask during the Iran-Iraq War.
These sources mention that Iraq invaded Kuwait to gain new oil wealth, expand access to the Persian Gulf, and reclaim Kuwait as part of Iraq. They also indicate that Iraq accused Kuwait of slant drilling oil wells along the border. Additionally, the sources mention the involvement of the United States and other nations in responding to the invasion.