Final answer:
Congress struggled to solve land disputes due to disagreements over treaty interpretations, powerlessness under the Confederation, and states wanting their own trade arrangements. The British and Spanish actions, recognizing Congress's weak enforcement power, complicated negotiations and policy establishment.
Step-by-step explanation:
The difficulty for Congress to solve land disputes with other nations arose from various factors, including disagreements over the interpretation of treaties, the lack of power under the Confederation, and the individual states' preference to make their own commercial arrangements. Specifically, issues with Great Britain, which included restrictions on American trade and refusal to evacuate trading posts, coupled with Spain's control over critical trade routes and disputed borders, posed significant challenges. These nations recognized the weakness of the Confederation Congress and doubted the enforcement of any commercial agreements, thus exacerbating the difficulties in establishing stable foreign and commercial policies.