Should a 2LT salute a 1LT?

No. Unless it's a 1LT serving as Company Commander. I feel it's like an E2 standing at parade rest for an E3. It's silly.

I saluted a 1LT and called him Sir once right after I commissioned. He was my company XO and I had been a cadet in the unit. He pulled me aside and told me the proper greeting between lieutenants is, "Sup."

A 1LT once told me that LT's (first or second) dont usually salute each other because its comparable to a PVT, PV2, or a PFC standing at parade rest for each other. Technically there suppose to but its hardly ever enforced.

I have been in the presence of 2LTs when they meet 1st LTS and they don't always render salutes but etiquette says you always salute a senior officer but you bet if a Major or higher walks in you bet a salute is given unless they are in the field.

Should an Officer Cadet salute a 2LT?

This is seriously a discussion? Is it that hard to just give a quick salute? If you don't like the customs and courtesies then you should probally have thought about joining the military a little bit harder.

This is a funny question. My battalion S3/XO used to always say, you are all Lieutenants, not one of you is better than the other because you all fail when one of you fails. Work together and you will excel.

Basically if a 1LT tries to hold seniority over a 2LT based on rank it can cause problems in getting stuff done.

That being said, a salute is a sign of respect, so if a 2LT salutes a 1LT, by regulation and intent he's not wrong. I just wouldn't have ever expected it or felt as though it was deserved when I was a 1LT.

I think it goes without saying, anytime someone has to use their rank to justify themselves, they are wrong. Through good leadership you should be able to influence people. Respect which is earned is better than respect tied to rank. 2LTs usually listen to and take direction from 1LTs because that 1LT actually knows whats going on. A young 2LT in our battery always listened to the 1LT XO because of respect and he was also situationally aware of his position.

Err on the side of caution, salute your superior 1t Lt until you are instructed not to by that 1t Lt.

yes, when I was a 2LT the 1LT told us not to, we continued that tradition though (in the company area aka our domain). However, elsewhere we showed the respect for the rank to eliminate others perception that we were not disciplined.

This is how you have two LTs with the same rank salute another.

AR 600-20
1–5. Hand salutes and salutes with arms
a. For instructions on executing the hand salute, see FM 3–21.5, paragraph 4–4.
b. All Army personnel in uniform are required to salute when they meet and recognize persons entitled to the salute.
Salutes will be exchanged between officers (commissioned and warrant) and enlisted personnel, and with personnel of
the Armed Forces of the United States (Army, Navy, Air Force, Marine Corps, Coast Guard), the commissioned corps
of the National Oceanic and Atmospheric Administration, and the commissioned corps of the Public Health Service
entitled to the salute.
c. The junior person shall salute first. Accompanying the rendering of the hand salute with an appropriate greeting
such as, "Good Morning, Sir" or "Good Morning, Ma’am" is encouraged. Personnel will not salute indoors except
when reporting to a superior officer

By reg the 2LT is junior to the 1LT. In theory he has to salute. If you go by the regs one step further you can have two officers in the same rank salute another.

In AR 600-20
2–7. Designation of junior in the same grade to command
The DCS, G–1 is responsible for policy on the designation of junior in the same grade to command.
a. When two or more commissioned officers of the same grade, both of whom are eligible to command, are
assigned to duty in the same command or organization, the President may assign the command of forces without regard
to seniority by DOR.
b. General officers are authorized to announce by direction of the President, the designation of one of several
officers of the same grade within a command under their jurisdiction as a commander thereof.
(1) This refers to general officers commanding ACOMs, ASCCs, or DRUs, armies, corps, installations, divisions,
separate brigades, regional support commands (RSCs), General Officer Commands (GOCOMs), and heads of DA staff
agencies. This may be done without regard to relative seniority. (See paras 2–5 and 2–8 for policy on general officers.)
When an officer who is junior by DOR is designated to command, a memorandum will be used to announce the
appointment and will contain the information shown in figure 2–2.

In this case the command may appoint a 1LT to be the CO when there are several 1LTs in the company. This appointment makes the other 1LTs junior to him and by the reg they would be requires to salute.

I actually witnessed this during AT this summer. A cadet who had been with our unit for a while received her commission in May. She approached one of our PLs and saluted, and he told her not to do that because they were both LTs. She was unsure of that advice, and after he left I said it is better to be told not to do it than to be dressed down for not saluting. The PL was a prior NCO, so I thought that might have had something to do with his thoughts on the matter.