The circuit is the following:

^{simulate this circuit – Schematic created using CircuitLab}

What is the equivalent resistance seen across Nodes 1 and 2? I am told it is R4 + R5. That means everything to the left is cut out.

1. Why can't current flow from across R3 to the left, into the short wire and bifurcate through the resistors R1 and R2, and back out through R3?

2. Why can't current flow across R3, into the short, and back out through the short?