The invasion into Iraq was Cheney's second choice. Originally, the Rumsfeld Cabal wanted to invade Iran for it's oil.
The USA invaded Iraq on March 19-20, 2003. That was 20 months before the 2004 elections. The Iraq invasion was a lie. The evidence presented to the United Nations was fabricated. But, the death toll of civilians for the Iraq War hovers around 200,000. That is the reported death toll. It is uncertain the complete death toll in Iraq. We may never know. Those deaths included women, children, the elderly and the disabled. They were people that could not protect themselves or escape to other countries like Jordan.
Bush entered Iraq for the second time since his father had in 1990 when Saddam Hussein invaded Kuwait. George H. W. Bush had a perfect reason to invade Iraq as it became a hostile neighbor to Kuwait. The Iraq invasion under "W" had no clear purpose and the idea it was responsible in any way for the attacks of September 11, 2001, is a complete lie that still lives on today.
But, we learned from H.W. Bush that Iraq fell all too easily. There was no reason from any standpoint to invade Iraq in 2003. But, the USA did and the Congress voted to reaffirm it. That was a very wrongful vote and only a small majority voted against it and became a sane voice afterward.
Iran is not that formidable. Additionally, morality within the international community falls to Iran. The USA was a member of a group of countries focused on non-proliferation of nuclear weapons. The USA, under Trump, and for political reasons (a campaign promise) left the international agreement. The USA, despite it's military might, is again acting immorally and illegally in stating an invasion into Iran is "not off the table."
Additionally, adding more troops to the region is not necessary. It will only serve to attract terrorists and increase the danger to the people of Iran and surrounding countries, including Iraq. The USA is stirring a pot that has just settled down for the most part after a very dangerous murdering militia called Daesh has been driven from the region.
There is no sound reason for Trump and Bolton to bring more troops to the region. If there is a greater threat to USA troops already there, then remove them. Bring the troops home for the Middle East. For the USA to carry out another illegal and highly immoral invasion into a sovereign country would only reinforce the idea that the USA can't be trusted and has lost all respect as a peace partner.
The USA Congress must vote down any declaration of war that Trump wants to use as a campaign tool.
Iran is not a threat to the USA.