In the event of a US-led response to alleged chemical weapons use in Syria, French and British forces have capabilities stationed in the region that could possibly be involved in any attack.
Having completed a major refit in the past few weeks, the French nuclear aircraft carrier Charles de Gaulle is operational. Officials say she remains for now in the Mediterranean port of Toulon.France also has Rafale and Mirage jets based in the United Arab Emirates that could potentially reach Syria.
Without any operational aircraft carriers, Britain would likely be dependent on its cruise missile-carrying Trafalgar and Astute class attack submarines if it wished to join in any US-led campaign.
Defense sources say the Royal Navy has kept at least one of its submarines in the Mediterranean in recent months partly for that reason.