The circumspect caution of General Howe afforded none.

After the repulse at Red Bank, his measures were slow but certain; and were calculated to insure the possession of the forts without exposing his troops to the hazard of an assault.
In this state of things, intelligence was received of the successful termination of the northern campaign, in consequence of which great part of the troops who had been employed against Burgoyne, might be drawn to the aid of the army in Pennsylvania.

But it was feared that, before these reinforcements could arrive, Sir William Howe would gain possession of the forts, and remove the obstructions to the navigation of the Delaware.

This apprehension furnished a strong motive for vigorous attempts to relieve fort Mifflin.

But the relative force of the armies, the difficulty of acting offensively against Philadelphia, and, above all, the reflection that a defeat might disable him from meeting his enemy in the field even after the arrival of the troops expected from the north, determined General Washington not to hazard a second attack under existing circumstances.
To expedite the reinforcements for which he waited, Colonel Hamilton was despatched to General Gates with directions to represent to him the condition of the armies in Pennsylvania; and to urge him, if he contemplated no other service of more importance, immediately to send the regiments of Massachusetts and New Hampshire to aid the army of the middle department.