Athens' strength in the Peloponnesian War came from its navy, whereas Sparta's came from its land-based Hoplite army. As the war progressed however the Spartans came to realize that if they were to undermine Pericles' strategy of outlasting the Peloponnesians by remaining within the walls of Athens indefinitely (a strategy made possible by Athens' Long Walls and fortified port of Piraeus), they were going to have to do something about Athens superior naval force. Once Sparta gained Persia as an ally, they had the funds necessary to construct the new naval fleets necessary to combat the Athenians. Sparta was able to build fleet after fleet, eventually destroying the Athenian fleet at the Battle of Aegospotami. The Spartan General Brasidas summed up the difference in approach to naval warfare between the Spartans and the Athenians: "Athenians relied on speed and maneuverability on the open seas to ram at will clumsier ships; in contrast, a Peloponnesian armada might win only when it fought near land in calm and confined waters, had the greater number of ships in a local theater, and if its better-trained marines on deck and hoplites on shore could turn a sea battle into a contest of infantry." In addition, compared to the high-finesse of the Athenian navy (superior oarsmen who could outflank and ram enemy triremes from the side), the Spartans (as well as their allies and other enemies of Athens) would focus mainly on ramming Athenian triremes head on. It would be these tactics, in combination with those outlined by Brasidas, that led to the defeat of the Athenian fleet at the Second Battle of Syracuse during the Sicilian Expedition.