Question

How did the articles of confederation make U.S weak?

Answer 1

The Articles were created by delegates from the states in the Second Continental Congress out of a need to have "a plan of confederacy for securing the freedom, sovereignty, and independence of the United States." After the war, nationalists, especially those who had been active in the Continental Army, complained that the Articles were too weak for an effective government. There was no president, no executive agencies, no judiciary and no tax base. The absence of a tax base meant that there was no way to pay off state and national debts from the war years except by requesting money from the states, which seldom arrived.

In 1788, with the approval of Congress, the Articles were replaced by the United States Constitution and the new government began operations in 1789.[9]

Source: wikipedia.org/wiki/Articles_of_Confederation

Answer 2

The articles of confederation had no division of powers (branches), the government was too weak to execute laws under the articles, the government couldn't collect taxes, couldn't form a military, etc.