Swords crossed as a saltire are seen in heraldry, either pointing upwards or downwards. The symbolism between the two orientations is quite different.
Pointing up'ards shows two swords ready for a fight.
Today, firearms are the favoured weapons for close combat; sword fights are restricted to movies like Pirates of the Caribbean and sport fencing. Raising his foil to invite the opponent to do likewise, the swordsman shouts "En garde!" as a warning that he is about to fight. (This assumes, of course, that the opponent knows what that French phrase means.)
The attacker would have more chance of success if he didn't shout the warning, but then he wouldn't be a gentleman.
Conversely, appel is a permitted tactic of stamping the foot to the ground to distract the opponent. This can accompany the en garde and negate the warning. Again, the fencer would have more chance of success if he stamped on his opponent's foot, but that's against the rules. Lunging at somebody with a sharp weapon is OK, but don't tread on their foot.
Always ready for a fight is the US Army and crossed sabres are used in an emblem of the United States Cavalry.
Crossed cutlasses appear in the coat of arms of Guatemala.
(See also Crosses on Flags)
Swords and other weapons pointing downwards imply the fight is over. Consequently downward-pointing swords may be seen engraved on a war memorial to honour those who fought and died in battle.
The coat of arms of Oman shows a Khanjar dagger over two downward-pointing scimitars. For over a thousand of years, Oman's geographic location has been politically and economically strategic for Indian Ocean trade leading to several conflicts and invasions in the distant past. The Sultanate of Oman now enjoys good relations with most countries, in particular its neighbours in the Middle East. For Oman, their swords are in their scabbards. The fighting is over.
Just 1,700 km northwest, however, the fighting is far from over.
People seem to favour up'ards.
The famous 'Hands of Victory' spanning the entrance of a parade ground in Baghdad was built by Saddam Hussein as a memorial to the soldiers who died in the Iran-Iraq War (1980-88). (Many observers consider the war ended in a stalemate, but both sides claimed victory.)
Where swords on memorials typically point downwards, the Hands of Victory point upwards in honour of the war's victims. Each 24-ton sword blade is reputed to include metal retrieved from the weapons of the soldiers who died. After the American invasion in 2003, the monument fell into disrepair, but the Iraqi government ordered its restoration in January 2011.
Islam does not own the copyright on crossed swords, of course. Here's one example in a Christian context, the flag of Vinnytsia in Ukraine.
The most common symbol of Islam is the Crescent but crossed scimitars are also prevalent, as seen in the emblem of Hamas, the coat of arms of Saudi and the Muslim Brotherhood.
Crossed Swords in Religion
As with Islam, in Christian symbolism swords pointing upwards show the readiness to fight evil. However, the downward pointing swords also have a place in Christianity, as explained above.
Downward pointing swords mean that the fighting is over. No more killing, no more battles, no more wars. It is then that mankind will have finally realised that the only thing (repeat; the only thing) that can fight and conquer evil is love.
As Jesus showed, love is not violent.