The shooting down of a Syrian fighter jet by US forces this week comes on the back of several aggressive actions by American military on the ground. Taken together the US actions mark an alarming escalation of intervention in the Syrian war – to the point where the Americans can be said to be now openly at war against Syria.

The American military actions also come despite repeated warnings from Russia against such unilateral deployment of force. Following the shoot-down of the Syrian SU-22 fighter bomber this week, Russian Foreign Minister Sergei Lavrov denounced the American violence as an act of "flagrant aggression" against a sovereign state. Some Russian lawmakers such as Duma foreign affairs chief Alexei Pushkov went further and condemned it as an act of war by the Americans.

Of course, Washington's logic is riddled with absurdity. To claim that its forces are acting in self-defense overlooks the glaring reality that the US-led military coalition has no legal mandate whatsoever to be in Syria in the first place. Its forces are in breach of international law by operating on Syrian territory without the consent of the government in Damascus and without a mandate from the UN Security Council.

Another absurdity is the claim that the US forces are "protecting" militants whom they are supposedly training to "fight" the Islamic State terror group (ISIS). On at least three occasions over the past month, American military have carried out air strikes on Syrian government forces and their allies near a strategically important border crossing between Syria and Iraq. The Americans claim that the Syrian government forces were posing a threat to a military base at Al Tanf on the Syrian side of the border where they are training militants belonging to a group called Maghawir al Thawra.

The Pentagon claims that these militants are being trained to "fight and defeat" ISIS. The installation last week of long-range artillery batteries known as HIMARS at Al Tanf was justified as a self-defense measure. US Colonel Ryan Dillon said: "We have increased our military footprint and are prepared for any threat that is presented to us by the pro-regime forces."

As with the shooting down of the Syrian fighter jet this week, American forces are invoking "self-defense" as a legal rationale. But as Moscow has pointed out, the Americans have no legal right to be present on Syrian territory and then, secondly, to be unilaterally declaring "deconfliction zones" for what are de facto invasive forces.

A further nail to the American lie is exposed when the nature of the militant group is looked at more closely. Unverified video footage showing the US-backed militants at Al Tanf indicates that they are another brand of jihadist terrorism. The videos show Maghawir al Thawra militants repeatedly shouting the jihadist slogan "allu akbar." They are also equipped with the notorious top-of-the-range white Toyota land cruisers that other jihadist groups have obtained through funding by Saudi Arabia and other Gulf monarchies.

Syrian sources have confirmed to this author that the group displayed in the videos is indeed the Maghawir al Thawra and that they are unquestionably jihadist. Yet this is the same group that the US has openly declared to be training at its military base at Al Tanf to "fight and defeat ISIS," and which the US is supposedly "protecting" from advancing Syrian army units and their allies.

What's more, it is reported that in addition to American forces at Al Tanf, there are British and other NATO troops, as well as those from two other Arab states. This amounts to a full-scale US-NATO intervention in the Syrian war – an intervention which seems to be clearly on the side of jihadist terror groups.