Question

what was the national government’s biggest concern if facing a war, under the articles of confederation?
the national government had no national military.
the country had grown too large to defend with a small army.
the states would not back the federal government.
there was no way the states would pay for fighting a war.

Explanation:

Under the Articles of Confederation, the national government (federal government) relied on the states to provide troops and resources. A key issue was that the states might not support the federal government in a war, as the Articles gave states significant sovereignty and the federal government had limited authority to compel states. The first option is incorrect because while the national government had a weak military, the bigger concern was state cooperation. The other options about the country's size or state payment aren't the primary concern related to the Articles' structure. So the correct reasoning points to the states not backing the federal government.

Answer:

The states would not back the federal government.