Rancher +Militia vs BLM,trouble on the range.(OT)

No one is obligated to remain passive in the face of direct violent threats, no matter who's doing the threatening.

Outside the USA[edit]
Australia[edit]
Australian states have several differing laws. However, under South Australian law, the general defence appears in s15(1) Criminal Law Consolidation Act 1935 (SA) for defending a person's life, and s15A(1) for defending property, subject to a hybrid test, i.e. the defendant honestly believed the threat to be imminent and made an objectively reasonable and proportionate response to the circumstances as the accused subjectively perceived them.[26]

In July 2003, the Rann Government (SA) introduced laws allowing householders to use "whatever force they deem necessary" when confronted with a home invader. Householders who kill or injure a home invader escape prosecution provided they can prove they had a genuine belief that it was necessary to do so to protect themselves or their family.

The law was strongly opposed by then-Director of Public Prosecutions Paul Rofe, QC, and lawyer Marie Shaw, who is now a District Court Judge.[27]

England and Wales[edit]
In English common law a defendant may seek to avoid criminal or civil liability by claiming that he acted in self-defence.[28] This requires the jury to determine whether the defendant believed that force was necessary to defend him or herself, his or her property, or to prevent a crime, and that the force used was reasonable.[29] While there is no duty to retreat from an attacker and failure to do so is not conclusive evidence that a person did not act in self-defence, it may still be considered by the jury as a relevant factor when assessing the merits of a self-defence claim.[28] The common law duty to retreat was repealed by the Criminal Law Act 1967. This duty never existed when a person is somewhere he has a lawful right to be, but due to the repeal, now extends to public places, etc.

Germany[edit]
German law allows self-defense against an unlawful attack.[30] Courts have interpreted this law as applicable to home invasion, including the use of lethal force against law enforcement in cases where the home owner was of the mistaken belief that the intrusion was unlawful.[31]

Israel[edit]
Israeli law allows property owners to defend themselves with force.[32] This law was introduced in response to the trial of Shai Dromi, an Israeli farmer who shot Arab intruders on his farm late at night.[33]

Italy[edit]
Italy passed a law in 2005 that would allow property owners to defend themselves with force.[34]

I believe it's pretty straighforward.

18USC SS 111 lays it out...you can't assualt, resist, or impede federal officers or employees in the conduct of their duties. When you brandish a deadly weapon in doing so, that elevates it to a felony.

Can you cite any US legal code or judicial precedent that permits anyone to engage a US officer with a firearm?

2nd Amendment rights are, IMHO, subject to reasonable disagreement. The 2nd Amendment itself was terribly drafted (in the drafters' defense, the concept of constitutional law didn't really exist back then, nor was "legal drafting" as a skill as developed of a concept). And the advances in weapons technology (which may or may not have been anticipated to some extent, but surely weren't fully anticipated) further could the issue.

Can you cite any US legal code or judicial precedent that permits anyone to engage a US officer with a firearm?

“My starting point and probably my ending point will be what limitations are within the understood limitations that the society had at the time,” he said. “They had some limitations on the nature of arms that could be borne. So we’ll see what those limitations are as applied to modern weapons.”